# Christopher G. Gray

## Research Topics

Molecular physics; molecular liquids, mixtures, and interfaces, molecular spectra, molecular chaos. Theoretical physics; new classical and semiclassical variational principles. Applied physics; supercritical fluid extraction, surfactant monolayers. Biophysics; ion channels, antimicrobial peptide-membrane intereactins, electron transfer reactions involving antioxidants, glucose tranporter proteins

Research Descriptions |
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Together with S. Goldman (Chemistry) we have received an NSERC-MRC Collaborative Grant (with P. Backx of the U. of T. Medical School, and R. Guy of N.I.H.), and a MRC equipment and personnel grant, to study ion channels in biomembranes. Together with posts-docs S. Hu and Igor Tolokh and M.Sc. students P. Weetman, G. White, and H. de Haan, we have carried out MD simulations at the atomic level, and examined simple electrostatic continuum models for K+ channels; of especial interest to us are the electrical conductance and selectivity. To perform the simulations, we have constructed a 50 processor Beowulf cluster and also have access to the Guelph-McMaster-Western-Windsor-Laurier SharcNet supercluster. Several papers on this subject have recently been published (see publications page). With undergraduate student Ilya Tolokh and the research group of P. Backx, we have a joint theoretical-experimental program to study cooperativity in the ion conduction process. Several papers have been published (see publication list). |

In collaboraiton with G. Karl and V. Novikov, we have filled a centuries-old gap in the literature; ie, the Maupertuis and Hamilton least action principles have been reformulated and completed (in the sense that reciprocal principles have been found for both). A direct connnection of the reciprocal Maupertuis principle to the Schrodinger quantum variational principle has been found. Applications to quantum chaos are currently being pursued (see Nonlinear Dynamics and Chaos below). A review of variational principles in classical, semiclassical and quantum mechanics has recently been published by us in Reports on Progress in Physics. |

In collaboration with postdoctorate fellows B. Yang and A. Denton, C.G. Gray and D.E. Sullivan have developed theoretical, simulation, and experimental techniques to study the perferred orientations of water molecules at the surface. The orientational structures of surfactant monolayers on water are also being investigated with former graduate student S. Opps; two papers on this topic have been published (see publications list). |

With former M.Sc. student G. Lee-Dadswell we have published two papers on the quantum chaos of the He@C70 system,based on the techniques developed in "Development of New Variational Principles" as described above. With now Ph.D. student G. Lee-Dadswell and in collaboration with B. Nickel we are studying a classic problem in solid state physics, ie, to explain microscopically Fourier's law of heat conductivity. We are beginning with one-dimensional chains with nonlinear springs, to try to understand the relation between the chaotic nature of the system and the establishment of Fourier's law. We have also studied the bulk viscosity for one-dimensional chains - see publication list. |

In collaboration with S. Goldman (Chemistry), M. LeMaguer and R. Lenki (Food Science), and T. Bose and A. St-Arnaud (Physics, Trois Rivierres), we received a strategic grant to develop the theory, laboratory experiments, and pilot plant (lab scale) to use SFE to extract value-added components of certain foods (eg. cumin oil from the seeds). Phase I (with S. Goldman and 2 Ph.D. students) has been completed. Three papers have been published on ab initio molecular theory of the SFE process, and a paper involving practical applications has been published in an engineering journal in collaboration with Feraal Temeli (Alberta) and as part of AFMNET (Advanced Food and Materials Network). We are currently studying extraction by SFE of anitoxidant molecules sucha s lycopene from the skins of tomatos. Bruno Tomberli (Physics Dept, Brandon University) is involved in this project. |

In collaboration with S. Goldman (Chemistry) and graduate student Nick Alessi we are investigating the vibrational line shifts of the fundamental and overtones for systems such as pure liquid N2, pure liquid HCl, liquid HCl-Ar mixtures etc. The N2 work has been published (see two papers in publication list). For a review of this subject, see C.G. Gray's publication list, paper number 141. |

As part of AFMNET and in collaboration with B. Tomberli, S. Goldman (Chemistry), I. Tolokh, and Ph.D. student Victor Vicharyak and the research groups of D. Pink (Physics, St. F.X.) and T. Beveridge (Microbiology, Guelph), we are studying (by computer simulations and experiment) how small polypeptides such as lactoferricin interact with and destroy bacterial membranes. The potential application is the developement of an alternative to traditional antibiotics, necessary because of antibiotic resistance developed by bacteria. |

As part of AFMNET and in collaboration with B. Tomberli and M.Sc. student Zhang Cui, we are studying by molecular dynamics computer simulation the electron transfer reactions of antioxidants such as lycopene with free radicals such as NO2. |

In collaboration with Mel Silverman (Faculty of Medecine, University of Toronto) and a Ph.D. student, we are measuring and simulating the transport rates for the glucose transporter membrane proteins GLUT1 and GLUT3. |

Most recently, in collaboration with K. Gubbins, North Carolina State University and former research associate C. Joslin, C.Gray has published Volume 2 (Applications) of "Theory of Molecular Fluids", Oxford University Press. |

## Recent Publications

- 192. P.J. Stiles and C.G.Gray (2020). Improved Hodgkin-Huxley-type Model for Action Potentials in Squid, J. Theoret. Biol., submitted (expanded version of #191)
- 191. P.J.Stiles and C.G.Gray (2019). Improved Hodgkin & Huxley-type Model for Action Potentials in Squid, arXiv 1908.05086, pp 1-29.
- 190. C.G.Gray and P.J.Stiles (2018). Nonlinear Electrostatics: the Poisson-Boltzmann Equation, arXiv 1803.02507, pp 1-70 (expanded version of #189).
- 189. C.G.Gray and P.J. Stiles (2018). Nonlinear Electrostatics: the Poisson-Boltzmann Equation, Euro. J. Phys. 39, 053002, pp 1-27.
- 188. C. G. Gray (2018). Book review - essay: The Lazy Universe: An Introduction to the Principle of Least Action, by Jennifer Coopersmith Am. J. Phys. 80, 395-399,
- 187. M. Nategholeslam, C. G. Gray, Bruno Tomberli (2017) Stiff-spring approximation revisited: inertial effects in non-equilibrium trajectories J. Phys. Chem. B, 121 (2), 391–403
- 186. M. Nategholeslam, C. G. Gray, Bruno Tomberli (2016) Stiff-spring approximation revisited: inertial effects in non-equilibrium trajectories arXiv:1607.07430
- 185. In Memoriam: Peter Egelstaff (2015) Physics in Canada, 71, 105-108.
- 184. S. Vafaei, B. Tomberli and C.G. Gray (2014) McMillan-Mayer Theory of Solutions Revisited: Simplifications and Extensions J. Chem. Phys, 141, 154501 (pp 1-18).
- 183. S. Vafaei, B. Tomberli and C.G. Gray (2014) McMillan-Mayer Theory of Solutions Revisited: Simplifications and Extensions ArXiv: 1406.1523 (extended version in publication # 184)
- 182. B.W. Holland, M.D. Berry, C.G. Gray and Bruno Tomberli (2014) A permeability study of O2 and the trace amine p-tyramine through model phospholipid bilayers PLOS One, 10.6: e0122468.
- 181. M. Nategholeslam, M. Nichols, L. DeBruin, M. Jelokhani-Niaraki, B. Tomberli and C. G. Gray (2014) A Molecular Dynamics and Conformational Study of the Antimicrobial Peptide HHC-36 To be submitted to BBA-Biomembranes
- 180. M. Nategholeslam , B. Tomberli, C. G. Gray (2014) Stiff-spring approximation revisited: correcting inertial effects in non-equilibrium trajectories Submitted to J. Chem. Phys.
- 179. M. Nategholeslam, M. Nichols, Lillian DeBruin, M. Jelokhani-Niaraki, B. L. Tomberli and C. G. Gray (2014) Molecular Dynamics and Calorimetry Study of the Interaction of the Antimicrobial Peptide HHC-36 with Phospholipid Membranes To be submitted to J. Phys. Chem. B
- 178. M. Nategholeslam , C. G. Gray and B. Tomberli (2014) Implementation of the Forward-Reverse Method for Calculating the Potential of Mean Force Using a Dynamic Restraining Protocol J. Phys. Chem. B, 118, 14203-14214
- 177. M. Nichols, M. Kuljanin, M. Nategholeslam, T. Hoang, S. Vafaei, B. Tomberli, C.G. Gray, L. DeBruin and M. Jelokhani-Niaraki (2013) Dynamic Turn Conformation of a Short Tryptophan-Rich Cationic Antimicrobial Peptide and Its Interaction with Phospholipid Membranes J. Phys. Chem. B, 117, 14697-14708.
- 176. B.W. Holland, C.G. Gray and B. Tomberli (2012) Calculating Diffusion and Permeability Coefficients with the Oscillating Forward-Reverse Method Phys. Rev. E, 86, 036707.
- 175. N. Kucerka, B.W. Holland, C. G. Gray, B. Tomberli and J. Katsaras (2012) Scattering Density Profile Model of POPG Bilayers As Determined by Molecular Dynamics Simulations and Small-Angle Neutron and X-ray Scattering Experiments J. Phys. Chem. B, 2012, 116 (1), pp 232–239.
- 174. C.G. Gray, K.E. Gubbins and C.G. Joslin (2011) Theory of Molecular Fluids. Volume 2: Applications. Oxford University Press, Oxford, 2011.
- 173. M. Nategholeslam, B.W. Holland, C.G. Gray and B. Tomberli (2011) Drift-oscillatory steering with the forward-reverse method for calculating the potential of mean force Phys. Rev. E 83, 021114 (12 pages).
- 172. C.G. Gray and E. Poisson (2011) When action is not least for orbits in general relativity Am. J. Phys. 79, 43-56.
- 171. S.G. Gregory, M. Jardine, C.G. Gray and J-F Donati (2010) The magnetic fields of forming solar-like stars Rep. Prog. Phys. 73 126901 (28 pages).
- 170. C.G.Gray, G.Karl and V.A. Novikov (2010) Magnetic Multipolar Contact Fields: The Anapole and Related Moments Am.J.Phys. 78, 936-948.
- 169. C.G. Gray (2009) Principle of Least Action Scholarpedia (13 pages) (access Scholarpedia from Google)
- 168. I.S. Tolokh, V.Vivcharuk, B. Tomberli and C.G. Gray (2009) Binding Free Energy and Counterion-Release for Adsorption of Antimicrobial Peptide Lactoferricin B with POPG Lipid Bilayer Phys. Rev. E 80, 031911 (12 pages).
- 167. C.G. Gray, G. Karl and V.A. Novikov (2009) Quadrupolar Contact Fields: Theory and Applications Am.J.Phys. 77, 807-817.
- 166. V.Vivcharuk, B. Tomberli, I.S. Tolokh and C.G. Gray (2008) Prediction of Binding Free Energy for Adsorption of Antimicrobial Peptide Lactoferricin B on POPC Membrane Phys. Rev. E77, 031913 (11 pages)
- 165. G.R. Lee-Dadswell, B.G. Nickel and C.G. Gray (2008) Detailed Examination of Transport coefficients in Cubic-Plus-Quartic Oscillator Chains J. Stat. Phys., 132, 1-33.
- 164. M.D.A. Saldana, F. Temelli, B. Tomberli, S.E. Guigand and C.G. Gray (2008) Solubility of Lycopene in Supercritical CO2 , CO2 + ethanol and CO2 + canola oil using Dynamic Extraction of Tomato J. Supercrit. Fluids, in press.
- 163. H.W. de Haan, I.S. Tolokh, S. Goldman and C.G. Gray (2006) Nonequilibrium molecular dynamics calculation of the conductance of the KcsA potassium ion channel Phys. Rev. E74, 030905 (4 pages).
- 162. I.S. Tolokh, S. Goldman and C.G. Gray (2006) Unified modeling of conductance kinetics for low- and high-conductance potassium ion channels Phys. Rev. E74, 011902 (12 pages).
- 161. B. Tomberli, S. Goldman, C.G. Gray, M.D.A. Saldana and F. Temelli (2006) Using Solute Structure to Predict Solubility of Organic Molecules in Supercritical Carbon Dioxide J. Supercrit. Fluids, 37, 333-341.
- 160. M.D.A. Saldana, B. Tomberli, S.E. Guigard, S. Goldman, C.G. Gray and F. Temelli (2007) Determination of Vapour Pressure and Solubility Prediction and Correlation of Phenolic Compounds in Supercritical CO2 J. Supercrit. Fluids, 40, 7-19.
- 159. C.G. Gray and E.F. Taylor (2007) When Action is Not Least Amer. J. Phys., 75, 434-458.
- 158. G.R. Lee-Dadswell, B.G. Nickel and C.G. Gray (2005) Thermal Conductivity and Bulk Viscosity in a Quartic Oscillator Chain Phys. Rev. E72, 031202 (8 pages).
- 157. G.R. Lee-Dadswell and C.G. Gray (2006) Semiclassical Variational Calculation of Energy Levels of He@C_70 Can. J. Phys., 84, 145-164.
- 156. N. Alesi, I.S. Tolokh, S. Goldman and C.G. Gray (2005) Simulation Study of N2 Overtone Solvent Shifts Using Improved Potentials Molec. Phys., 103, 2381-2396.
- 155. N.D'Avanzo, H.C.Cho, I.I.Tolokh, R.Pekletski, I.S.Tolokh, C.G.Gray, S.Goldman and P.H.Backx (2004) Conduction Through the Inward Rectifier Potassium Channel, Kir2.1 is Increased by Negatively Charged Extracellular Residues J. Gen. Physiol., 125, 493-503.
- 154. I.S. Tolokh, I.I. Tolokh, H.C. Cho, N. D'Avanzo, P.H. Backx, S. Goldman and C.G. Gray (2005). Non-Michaelis-Menten kinetics model for conductance of low-conductance potassium ion channels Phys. Rev. E 71, 021906 (9 pages).
- 153. N. Alesi, I.S. Tolokh, S. Goldman and C.G. Gray (2004) Simulation Study of Solvent Shifts of Vibrational Overtone Spectra Molec. Phys., 102, 2037-2047.
- 152. C. G. Gray, G. Karl and V. Novikov (2004) Progress in Classical and Quantum Variational Principles Reports on Progress in Physics, 67, 159-208.
- 151. D. Petrie, J.L. Hunt, and C.G. Gray (2002) Does the Euler Disk Slip During its Motion? Amer. J. Phys., 70, 1025-8.
- 150. I.S. Tolokh, G. White, S. Goldman and C.G. Gray (2002) Prediction of Ion Channel Transport From Grote-Hynes and Kramers Theories Molec. Phys., 100, 2351-9.
- 149. B. Tomberli, S. Goldman and C.G. Gray (2001) Predicting Solubility in Supercritical Solvents Using Estimated Virial Coefficients and Fluctuation Theory Fluid Phase Equilibria. 187-88, 111-130.
- 148. S.B. Opps, B. Yang, C.G. Gray and D.E. Sullivan (2001) Monte Carlo Studies of Model Langmuir Monolayers Phys. Rev. E 63, 41602-13.
- 147. C.G. Gray, G. Karl and V. Novikov, (2000) From Maupertuis to Schrodinger. Quantization of Classical Variational Principles Amer. J. Phys. 67, 959-61.
- 146. C.G. Gray and B.G. Nickel, (2000) Constants of the Motion for Nonslipping Tippe Tops and Other Tops with Round Pegs Amer. J. Phys. 68, 821-8.
- 145. S.B. Opps, B.G. Nickel, C.G. Gray and D.E. Sullivan, (2000) The Ground State Behaviour of Model Langmuir Monolayers J. Chem. Phys. 113, 339-48.
- 144. G.R. Lee-Dadswell and C.G. Gray, (2000) Semiclassical Calculation of Quantum Energy Levels Using Variational Principles: Application to He@C70 Can. J. Phys. 78, 599-616.
- 143. G.W.N. White, S. Goldman and C.G. Gray, (2000) Test of Rate Theory Transmission Coefficient Algorithms. An Application to Ion Channels Molec. Phys. 98, 1871-85.
- 142. J. Hu, S. Goldman, C.G. Gray and H.R. Guy (2000) Calculation of the Conductance and Selectivity of an Ion-Selective Potassium Channel (IRK1) from Simulation of Atomic Scale Models Molec. Phys. 98, 535-47.
- 141. C.G. Gray and C.G. Joslin (1997) Solvent Effects in Vibrational Spectra, in Optical, Electric and Magnetic Properties of Molecules: a Review of the Work of A.D. Buckingham ed. D. Clary and B. Orr, Ch. 7, Elsevier.
- 140. P. Weetman, S. Goldman and C.G. Gray (1997) The Use of the Poisson-Boltzmann Equation to Estimate the Free Energy Barrier for Dielectric Models of Biological Ion Channels J. Phys. Chem. B101, 6073-8.
- 139. C.G. Gray, S. Goldman, B. Tomberli and W. Li (1997) Correlation Lengths and Density Fluctuations in Supercritical States of Carbon Dioxide Chem. Phys. Lett.. 271, 185-7.
- 138. C.G. Gray, G. Karl and V. Novikov (1997) From Schrodinger to Maupertuis. Least Action Princples from Quantum Mechanics Proc. MRST Conf., World Scientific.
- 137. C.G. Joslin, C.G. Gray and S. Goldman, (1995) Infrared Rotation and Vibration-Rotation Bands of Fullerene Complexes. He@C70 Chem. Phys. Lett. 244, 93-9.
- 136. C.G. Joslin, C.G. Gray, S. Goldman, B. Tomberli and W. Li, (1996) Solubilities in Supercritical Fluids from Virial Equation of State Molec. Phys. 89, 489-503.
- 135. S. Goldman, C.G. Gray, W. Li, B. Tomberli and C.G. Joslin, (1996) Predicting Solubilities in Supercritical Fluids J. Phys. Chem. 100, 7246-9.
- 134. C.G. Gray, G. Karl and V.A. Novikov, (1996) The Four Variational Principles of Mechanics Ann. Phys. 251, 1-25.
- 133. C.G. Gray, G. Karl and V.A. Novikov, (1996) Direct Use of Variational Principles as an Approximation Technique in Classical Mechanics Amer. J. Phys. 64, 1177-84.
- 132. C.G. Joslin, S. Goldman and C.G. Gray, (1994) Calculation of Infrared Spectra of Endohedral Complexes of Bucky Tubes Chem. Phys. Lett. 215, 144-50.
- 131. C.G. Joslin, J. Yang, C.G. Gray and S. Goldman, (1994) Vibrational Spectra of Fullerenes, Proc. Mexican 1994 Winter School on Statistical Mechanics.
- 130. A.R. Denton, C.G. Gray and D.E. Sullivan, (1994) Orientational Ordering of Surfactant Monolayers Adsorbed at the Air-Water Interace: Structural Model and Fit to Neutron Reflectivity Data Chem. Phys. Lett. 219, 310-18.
- 129. B. Yang, D. Sullivan and C.G. Gray, (1994) Density Functional Theory of the Water Liquid Vapour Interface II J. Phys. Condens. Matter 6, 4823-42.
- 128. W. Glaz, J. Yang, J.D. Poll and C.G. Gray, (1994) Complex Plane Method for Interaction-induced Spectra in 3D Systems Chem. Phys. Lett. 218, 183-8.
- 127. C.G. Gray, C. Joslin, J. Poll, S. Goldman and A.D. Buckingham, (1995) Prediction of Induced Spectra of Endohedral Buckyball Complexes NATO Advanced Workshop on Induced Spectra, ed. G. Tabisz, Plenum.
- 126. C.G. Gray, C. Joslin and J. Poll, (1995) Theory of Induced Spectral Wings NATO Advanced Workshop on Induced Spectra, ed. G. Tabisz, Plenum.
- 125. C.G. Joslin, J. Yang, C.G. Gray, S. Goldman and J.D. Poll, (1993) Infrared Rotation and Vibration-rotation Bands of Endohedral Fullerene Complexes. K+ @ C60 Chem. Phys. Lett. 211, 587-94.
- 124. C.G. Joslin, J. Yang, C.G. Gray, S. Goldman and J.D. Poll, (1993) Infrared Rotation and Vibration-rotation Bands of Endohedral Fullerene Complexes. Absorption Spectrum of Li+ @C60 in the Range 1-1000 cm-1 Chem. Phys. Lett. 208, 86-92.
- 123. C.G. Joslin, C.G. Gray, J.D. Goddard, S. Goldman, J. Yang and J.D. Poll, (1993) Infrared Rotation and Vibration-rotation Bands of Endohedral Fullerene Complexes. He @ C60 Chem. Phys. Lett. 213, 377-82.

## Older Publications

- 122. C.G. Joslin, C.G. Gray, S. Goldman, J. Yang and J.D. Poll, (1993). Raman Spectra of Endohedral Fullerenes. Li+ @ C60, Chem. Phys. Lett. 215, 144-50.
- 121. Calculation of the Quantum Mechanical Propagator at Large Real Times, Computer Phys. Commun., 75, 1-9 (1992) (with C. Joslin, J. Poll).
- 120. Molecular Orientational Structure of the Water Liquid/Vapour Interface. J. Phys. Cond. Matter, 3, F109-25 (1991) (with B. Yang, D.E. Sullivan and B. Tjipto-Margo).
- 119. Comment on: Molecular Orientation Near Liquid-Vapour Interface of Methanol: Simulational Study. J. Chem. Phys., 95, 7777 (1991) (with B. Yang and D.E. Sullivan).
- 118. Measurement of Amplitude Jumps and Hysterisis in a Driver Inverted Pendulum. Amer. J. Phys., 60, 755-6 (1992) (with N. Alessi and C.W. Fischer).
- 117. Collision-Induced Absorption in Cyclopropane.Can. J. Phys., 70, 134-9 (1992) (with I.R. Dagg, A. Anderson, W. Smith, P.J. Reid and C.G. Joslin).
- 116. Density-Functional Theory of the Water Liquid-Vapour Interface. Molec. Phys., 76, 709-35 (1992) with (B. Yang, D.E. Sullivan and B. Tjipto-Margo).
- 115. Improved Short-time Propagator for Repulsive Inverse Power-law Potentials. Chem. Phys. Lett., 177, 64-72 (1991) (with L.I. Lolle, J.D. Poll and A.G. Basile).
- 114. A Relaxation Algorithm for Classical Paths as a Function of End-Points: Application to the Semiclassical Propagator for Far-from-Caustic and Near-Caustic Conditions. J. Computational Phys., 101, 80-93 (1992) (with A.G. Basile).
- 113. Collision-induced Absorption in Gaseous SF6. Can. J. Phys., 69, 671-8 (1991) (with I.R. Dagg, A. Anderson, T. Gmach, W. Smith and C.G. Joslin).
- 112. Inexpensive and Accurate Position Tracking with a Ranging Module and a Microcomputer. Amer. J. Phys., 59, 998-1002 (1991) (with B. Duchesne and C.W. Fischer).
- 111. Chaos in the Motion of an Inverted Pendulum; an Undergraduate Laboratory Experiment. Amer. J. Phys., 59, 987-92 (1991) (with B. Duchesne, C.W. Fischer and K.R. Jeffrey).
- 110. Calculation of High Frequency Spectral Wings by Solution of the Schr?dinger Equation in the Complex Plane. Chem. Phys. Letters, 175, 105-110 (1990) (with J. Yang, B.G. Nickel, J.D. Poll and A.G. Basile).
- 109. Comment on "Fisher Information as the Basis of the Schr?dinger Equation". Amer. J. Phys., 59, 282 (1991).
- 108. Proc. Sixth Conference on Line Shapes, NATO, Plenum, Univ. of Texas, Austin, June 1990, Complex Plane and Path Integral Methods for Calculating High Frequency Spectral Wings (with J. Poll).
- 107. Computer Simulation Study of Bulk Viscosity of Square Well Fluids. Molec. Phys. 69, 535-47 (1990) (with C. Joslin, J. Karkheck, J. Michels).
- 106. Calculation of Transport Coefficients using a Modified Mori Formalism II. The Diffusion Coefficient for a Dilute Gas of Hard Spheres. Molec. Phys. 66, 757-65 (1989) (with C. Joslin).
- 105. Line-shape in Collision-induced Absorption: Classical, Quantum and Semiclassical Calculations for Exactly Solvable Models, Molec. Phys. 66, 961-79 (1989) (with A. Basile, B. Nickel and J. Poll).
- 104. Far-infrared absorption in Liquid Carbon Tetrachloride: Theoretical Study of the Line shape and Intensity. Chem. Phys. Lett. 154, 369-73 (1989) (with C. Joslin).
- 103. Theory and Simulation of Associating Liquid Mixtures, Part II. Molec. Phys., 62, 843-60 (1987) (with K. Gubbins et al).
- 102. Comments on: About an Information Theoretical Spectral Line Shape proposed for Collision-Induced Spectroscopies, Mol. Phys., 64, 997-1000 (1988) (with C. Joslin and D. Sullivan).
- 101. Theory and Simulation of Hydrogen Bonding in Liquids. Fluid Phase Equilibria 29, 337-346 (1986) (with G.W. Chapman, K.E. Gubbins, C.G. Joslin).
- 100. Mixtures of Polar and Associating Molecules. Pure and Applied Chemistry 59, 53 (1987) (with W.G. Chapman, K.E. Gubbins, C.G. Joslin).
- 99. Lineshape in Collision-induced Absorption Spectra. Theory and Computer Simulation for Atomic and Simple Molecular Species. Molec. Phys., 60, 95 1975 (1987). (with G.B. Nickel, J.D. Poll, Y.S. Sainger, S. Singh and S. Weiss).
- 98. Calculation of Transport Coefficients Using a modified Mori Formalism. Molec. Phys. 58, 789-797 (1986). (with C.G. Joslin)
- 97. Computer simulation of dipolar fluids. Dependence of the dielectric constant on system size: A comparative study of the Ewald sum and reaction field approaches. J. Chem. Phys., 85, 1502-1504, (1986) (with Y.S. Sainger, C.G. Joslin, S. Goldman and P. Cummings).
- 96. The second dielectric virial coefficient of a dipolar sticky hard sphere fluid. Molec. Phys. 57, 1197-1200 (1986) (with C.G. Joslin).
- 95. Line shape in collision-induced absorption spectra. Comparison of theory and computer simulation. Molec. Phys. 57, 253-262 (1986) (with B.G. Nickel, J.D. Poll, S. Singh and S. Weiss).
- 94. Far infrared absorption in liquid methane: A theoretical study, Mol. Phys., 55, 1075-1087 (1986) (with C. Joslin and S. Singh).
- 93. Information theory of the lineshape of Collision induced absorption: liquid tetrafluoramethane, Chem. Phys. Lett., 121, 134-138 (1986) (with C.G. Joslin and S. Singh).
- 92. Far infrared absorption in liquid methane argon mixtures, Molec. Phys. 55, 1089 - 1096 (1986) (with C. Joslin).
- 91. Maximum Entropy and the Moments Problem: Spectroscopic Applications, in Proceedings of the Conference on Maximum Entropy and Bayesian Methods in Applied Statistics, University of Calgary, J. Justice (ed.), Cambridge Univ. Press (1986), pp. 194-206.
- 90. Collision induced absorption in N2 at Various Temperatures, in Phenomena induced by intermolecular interactions, ed. G. Birnbaum ( NATO conference at Bonas, France), Plenum (1985), pp. 109-18 (with I.R. Dagg).
- 89. Calculation of Spectral moments for Induced Absorption in Liquids, in Phenomena induced by intermolecular interactions, ed. G. Birnbaum (NATO conference at Bonas, France), Plenum. (1985), pp. 383-98 (with C.G. Joslin).
- 88. Far infrared Absorption in Liquid Nitrogen: A Theoretical Study, Can. J. Phys., 63, 76 (1985) (with C. Joslin, S. Singh).
- 87. Thermodynamic properties of liquid mixtures of Hydrogen Chloride and Tetrafluoremethane, Fluid Phase Equilibria, 22, 89-105 (1985) (with L. Lobo, L. Stavely, K. Gubbins, C. Joslin).
- 86. Far infrared absorption in gaseous CH4: A Theoretical Study, Molec. Phys., 54, 1169-1189 (1985) (with C. Joslin, S. Singh).
- 85. The Effect of Non axial Quadrupole Forces on the Anisotropy of Mean Squared Force and Torque, Chem. Phys. Lett. 104, 407 (1984) (with K. Gubbins and S. Murad).
- 84. Renormalized Perturbation Theory for Dipolar and Quadrupolar Polarizable Liquids, Molec. Phys., 54, 1117-1128 (1985) (with C. Joslin, K. Gubbins, V. Venkat).
- 83. Induction Effects in Fluid Mixtures of Dipolar Quadrupolar Polarizable Molecules, Molec. Phys. Phys., 54, 1129-1148 (1985) (with C. Joslin, K. Gubbins, V. Venkat).
- 82. Far infrared Absorption in Nitrogen Gas: a theoretical study, Mol. Phys. 52, 203-223 (1984) (with C. Joslin, Z. Gburski).
- 81. Induction Effects in Polar Polarizable Liquid Mixtures: Calculation of Thermodynamic properties using Renormalized Perturbation Theory, Molec. Phys. 52, 1411 (1984) (with C. Joslin and K. Gubbins).
- 80. Multipole expansions in four dimensions. J. Phys. A., 17 1313 (1984) (with C.G. Joslin).
- 79. Collision induced absorption line shape for rare gases. Mori theory. Chem. Phys. Lett., 106, 55 (1984) (with Z. Gburski and D. Sullivan).
- 78. Structure of a diatomic fluid near a wall. II. Lennard Jones fluid. Molec. Phys., 51, 21 (1984) (with D. Sullivan, S. Thompson and K. Gubbins).
- 77. Evaluation of the CPY and PYX approximations for short ranged anisotropic potentials. Molec. Phys., 50, 1183 (1983) (with P. Cummings, J. Ram and M. Wertheim).
- 76. Multipole expansions in two dimensions. Molec. Phys., 101, 248 (1984) (with C.G. Joslin).
- 75. Effective central potentials for molecular fluids. Chem. Phys. Lett., 101, 248 (1984) (with C.G. Joslin).
- 74. The Effect of Non axial Quadrupole Forces on Liquid Properties, Chem. Phys. Letters. 95, 541 (1983) (with C. Joslin and K. Gubbins).
- 73. Information theory of line shape in collision induced absorption. Chem. Phys. Lett., 100, 383 (1983) (with Z. Gburski and D. Sullivan).
- 72. Higher order spectral moments in collision induced absorption. Inert gas mixtures. Chem. Phys. Lett. 95, 430 (1983) (with Z. Gburski and D. Sullivan).
- 71. Comparisons of perturbation and integral equation theories for the angular pair correlation function in molecular fluids. Chem. Phys. 81, 87 (1983). (with S. Murad and K. Gubbins)
- 70. The effect of nonaxial quadrupole forces on liquid properties. Chem. Phys. Lett. 95, 541 (1983) (with S. Murad and K. Gubbins).
- 69. Evaluation of the SSC, SSCF and PY approximations for short ranged anisotropic potentials. Molec. Phys. 48, 1177 (1983) (with M. Wertheim, P. Cummings, J. Ram and R. Barker).
- 68. Structure of a diatomic fluid near a Wall, I. Molec. Phys. 44, 597 (1981) (with D. Sullivan, W. Streett and K. Gubbins).
- 67. Auxiliary sites in the RISM approximation for molecular fluids. J. Phys. A, 14, 1483 (1981) (with P. Cummings and D. Sullivan).
- 66. Evaluation of angular correlation parameters and the dielectric constant in the RISM approximation. Molec. Phys. 42, 443 (1981) (with D. Sullivan).
- 65. Spherical harmonic expansions of the angular pair correlation function in molecular fluids. Chem. Phys. Lett. 76, 583 (1980) (with J. Haile).
- 64. Thermodynamics of liquid mixtures of xenon and carbon tetrafluoride. J. Chem. Soc. Farad. Trans. I 77, 425 (1981) (with L. Staveley and K. Gubbins et al.).
- 63. Theory of fluids of nonaxial quadrupolar molecules. II. Structural and spectroscopic properties. Molec. Phys. 42, 843 (1981) (with K. Gubbins).
- 62. Theory of fluids of nonaxial quadrupolar molecules. I. Thermodynamic properties. Molec. Phys. 42, 817 (1981) (with K. Gubbins).
- 61. Determination of the quadrupole moment tensor of ethylene by collision induced absorption. Chem. Phys. Lett. 73, 278 (1980) (with K. Gubbins, I. Dagg and L. Read).
- 60. Mean field theory of molecular liquids. II. Thermodynamic properties. Can. J. Phys. 57, 1605 (1979) (with R.L. Henderson).
- 59. Second order perturbation theory for the angular pair correlation function in molecular fluids. Chem. Phys. Lett. 65, 187 (1979) (with S. Murad and K. Gubbins).
- 58. On the definition of the magnetic quadrupole moment. Am. J. Phys. 48, 984 (1980).
- 57. Spherical harmonic expansion of the intermolecular site site potential. Molec. Phys. 37, 129 (1979)., (with K. Gubbins et al.)
- 56. Magnetic multipole expansions using the scalar potential. Am. J. Phys. 47, 457 (1979).
- 55. Debye potential representation of vector fields. Am. J. Phys. 46, 735 (1978) (with B. Nickel).
- 54. Perturbation theory for molecular fluids: Third order term in the Pople expansion. J. Chem. Phys. 69, 182 (1978) (with K. Gubbins and C. Twu).
- 53. Thermodynamics of polar liquid mixtures. Disc. Faraday Soc. 66, 116 (1979) (with P. Clancy and K. Gubbins).
- 52. Comments on theory of molecular liquids. Disc. Faraday Soc. 66, 176, 178, 301 (1978).
- 51. Thermodynamics of liquid mixtures involving hydrogen bromide, hydrogen chloride and xenon. J. Chem. Soc. Faraday Trans. I 74, 893 (1978) (with L. Stavely and K. Gubbins).
- 50. Simplified derivation of the magnetostatic multipole expansion using the scalar potential. Am. J. Phys. 46, 582 (1978).
- 49. Multipole expansion of electromagnetic fields using Debye potentials. Am. J. Phys. 46, 169 (1978).
- 48. Thermodynamic derivatives of correlation functions. Molec. .Phys. 35, 315 (1978) (with P. Egelstaff and K. Gubbins).
- 47. Theory of the pair correlation function in molecular liquids. Can. J. Phys. 56, 571 (1978) (with R.L. Henderson).
- 46. Thermodynamics of mixtures of nonspherical molecules. III. Fluid phase equilibria and critical loci. J. Chem. Phys. 64, 5185 (1976) (with C.Twu and K.E. Gubbins).
- 45. Theory of collision induced absorption in liquids. I. Rare gas liquids. Molec. Phys. 32, 989 (1976) (with J.D. Poll and K.E. Gubbins).
- 44. Theory of surface tension for molecular liquids. II. Perturbation theory calculations. J. Chem. Phys. 64, 2569 (1976) (with K. Gubbins et al).
- 43. Monte Carlo simulation of molecular fluids on a minicomputer. J. Comp. Phys. 21, 227 (1976) (with R. McPherson, D. Litchinsky, K. Gubbins and J. M. Haile).
- 42. Vapour liquid interfacial density orientation profiles for fluids with anisotropic potentials. J. Chem. Phys. 64, 1852 (1976) (with K. Gubbins and J. Haile).
- 41. Spherical tensor theory of molecular polarizabilities. Chem. Phys. 14, 73 (1976) (with B. Lo).
- 40. Thermodynamics of mixtures of nonspherical molecules. II. Strong polar, quadrupolar and overlap forces. Molec. Phys. 30, 1649 (1975) (with K.E. Gubbins and M. Stephanopoulos).
- 39. Calculation of the dielectric and Kerr constant angular correlation parameters. Molec. Phys. 30, 1481 (1975) (with K. Gubbins).
- 38. Theory of inelastic neutron scattering from molecular liquids. J. Stat. Phys. 13, 315 (1975) (with K.E. Gubbins, P.A. Egelstaff and K. Mo).
- 37. Mean squared torque in dense fluids: Strong polar and quadrupolar forces. Molec. Phys. 30, 1607 (1975) (with K. Gubbins and C. Twu).
- 36. Equilibrium statistical mechanics of polyatomic liquids. Specialists Periodical Reports 34, Statistical Mechanics 2 (Chemical Society of London), ed. K. Singer, (1975).
- 35. Moment analysis and quantum effects in collision induced absorption. Molec. Phys. 29, 825 (1975) (with J.D. Poll and M.S. Miller).
- 34. Spherical tensor approach to multipole expansions. II. Magnetostatic interactions. Can. J. Phys. 54, 512 (1976) (with P. Stiles).
- 33. Spherical tensor approach to multipole expansion. I. Electrostatic interactions. Can. J. Phys. 54, 505 (1976).
- 32. New rotational transition in the hydrogen molecule. Phys. Rev. Lett. 33, 256 (1974) (with J.L. Hunt et al.).
- 31. Equilibrium properties of molecular fluids. M.T.P. International Review of Science (1974), ed. A.D. Buckingham, (with P.A. Egelstaff and K.E. Gubbins).
- 30. Thermodynamic inequalities for molecular fluids. Molec. Phys. 30, 881 (1975) (with R. Henderson).
- 29. Theory of surface tension for molecular liquids. Molec. Phys. 30, 179 (1975) (with K.E. Gubbins).
- 28. Excess thermodynamic properties for liquid mixtures of non spherical molecules. Molec. Phys. 29, 713 (1975) (with C.H. Twu and K. Gubbins).
- 27. Monte Carlo calculations of mean square force in molecular liquids. Chem. Phys. Lett. 26, 610 (1974) (with S. Wang and K. Gubbins).
- 26. Dipole moment of three interacting rare gas atoms. Chem. Phys. Letts. 25, 55 (1974) (with B. Lo).
- 25. Monte Carlo study of angular pair correlation function in a liquid with quadrupolar forces. Chem. Phys. Lett. 24, 453 (1974) (with K. Gubbins, P.A. Egelstaff and S.S. Wang).
- 24. Calculation of the pressure broadening of HCl and DCl infra red and Raman lines. J. Chem. Phys. 61, 418 (1974).
- 23. Calculation of the third depolarization virial coefficient for monatomic gases. Molec. Phys. 27, 1683 (1974) (with H. Ralph).
- 22. Mean squared torque in pure and mixed dense fluids. Molec. Phys. 27, 1601 (1974) (with K.E. Gubbins and C.H. Twu).
- 21. Perturbation theory for equilibrium properties of molecular fluids. Molec. Phys. 28, 1005 (1974) (with K.E. Gubbins and M. Ananth).
- 20. Monte Carlo study of the pair correlation function with a liquid with non central forces. Chem. Phys. Lett. 21, 123 (1973) (with P.A. Egelstaff, S.S. Wang and K.E. Gubbins).
- 19. Angular correlation effects in neutron diffraction from molecular fluids. Molec. Phys. 25, 1353 (1973) (with K. Gubbins, P.A. Egelstaff and M. Ananth).
- 18. Multipole interactions for time dependent fields. J. Phys. A. 6, 59 61 (1973) (with L. Barron).
- 17. Solution of Boltzmann's equation for semiconductors using a spherical harmonic expansion. J. Phys. C. 5, 55 62 (1972), (with H. Ralph).
- 16. Classical theory of pressure broadening. Am. J. Phys. 40, 491 (1972).
- 15. J dependent pressure shifts in infrared and Raman spectra. Chem. Phys. Lett. 13, 260 (1972) (with R. Tipping).
- 14. Perturbation theory for the angular pair correlation function in molecular fluids. Molec. Phys. 23, 187 (1972) (with K.E. Gubbins).
- 13. Theory of collision induced absorption for spherical top molecules. J. Phys. B4, 1661 1669 (1971).
- 12. Pressure broadening of the rotational Raman lines of HCl. Chem. Phys. Letts. 8, 527 (1971).
- 11. Density hierarchy for the time dependent correlation functions. Phys. Lett. 37A, 321 (1971) (with K.E. Gubbins and P.A. Egelstaff)
- 10. Collision induced rotational translational spectrum for octopolar molecules. J. Chem. Phys. 55, 459 (1971).
- 9. Intermolecular force effects in the Raman spectrum of gases. Ch. 7. In Essays in Structural Chemistry. Edited by D. Long et al. pp. 188, MacMillan (1970) (with H.L. Welsh).
- 8. Virial expansion for the depolarization ratio of Rayleigh scattering from monatomic gases. Phys. Lett. 33A, 165 166 (1970) (with H. Ralph).
- 7. Calculation of the pressure broadening of infrared and Raman spectra. J. Chem. Phys. 53, 457 (1970).
- 6. One particle self energy and the virial coefficients. Phys. Rev. 182, 235 243 (1969).
- 5. Anisotropic intermolecular forces for CH4 Ar. J. Chem. Phys. 50, 549 (1969).
- 4. Remarks on integral orbital angular momentum. Am. J. Phys. 37, 559 560 (1969).
- 3. Infrared spectra, rotational correlation functions and intermolecular mean squared torque in compressed gaseous methane. Can. J. Phys. 46, 1331 1340 (1968) (with S. Blumenfeld and R. Armstrong).
- 2. On the theory of multipole interactions. Can. J. Phys. 46, 135 139 (1968).
- 1. Calculation of the pressure broadening of rotational Raman lines due to anisotropic intermolecular forces. Can. J. Phys. 44, 2411 2430 (1966) (with J. Van Kranendonk).

## On Site Systems

- 4 Alpha processors at 500 Mhz
- Silicon Graphics Origin 200
- 2 Silicon Graphics Indy Workstations
- 3 2.4 GHz AMD Athlon 64 workstations

## Beowulf Cluster Computer

Igor Tolokh of the Guelph Ion Channel Group constructed a 48 processor "baby beowulf" cluster. It is dedicated to ion channel and other protein simulations and is housed in the Faculty of Medicine at the University of Toronto. The Guelph team is part of a Membrane Research Group of Toronto, and all members of the group have access to the Beowulf. Typically, a user employs eight processors in parallel for the simulations.

## SharcNet: Supercomputer Clusters

Together with partner institutions Western, McMaster, Waterloo, Laurier, and Windsor, U of G computational researchers have accesss to SHARCNET facilities: twenty supercomputer clusters (8098 CPUs, 14 TB memory, 300 TB hard drive storage). Typical channel simulations use 16 or 32 processors, and speed up the simulations by two orders of magnitude compared to the single processor workstations previously used by the group.