New Software Expands Role Of Molecular Modeling Technology

Relationship Between Physical Properties and Crystal Structures of Chiral Drugs

“…35,36 One of the major advantages of computer modeling over experiment is that the interaction energy and its variation with structure may be investigated at the atomic and molecular levels. Important aspects of molecular modeling include quantum theory, molecular mechanics, molecular dynamics, computer graphics, computerized algorithms, and model design.…”

Molecular Modeling Study Of Chiral Drug Crystals: Lattice Energy Calculations

“…Molecular modeling uses computational methods to study various chemical and biological systems. In recent years this technique has emerged as an important tool for predicting and correlating the energies and properties of molecules of known and unknown structures in chemical, biological, and pharmaceutical research 1,2. One of the major advantages of computer modeling over experiment is that the interaction energy and its variation with structure may be investigated at the atomic and molecular levels.…”

“…The modeling approach in materials research is greatly facilitated by improvements and accessibility of computer power and the emergence of user‐friendly molecular modeling packages. Cerius2 is one of the software packages that provides a full suite of modeling and simulations, capable of solving diverse problems in materials research.…”

“…Although considerable attention has been directed to the problem of selecting appropriate values for the atomic point charges, electrostatic potential calculations remain problematic 14,16. The method available in Cerius2, release 1.6, is the charge equilibrium (QEq) method based on the equilibrium potential 17. In this study, the atomic charges assigned by the QEq method were comparable to those obtained by various ab initio methods, and were used for the calculations of the electrostatic energy.…”

“…It is known that the distance between the hydrogen bond donor and acceptor atoms is usually less than the sum of the van der Waals radii, so that the Lennard‐Jones 12‐6 potential function may not be appropriate for calculating E H 16. For lattice energy calculations in Cerius2, the hydrogen‐bonding energy is calculated using a CHARMm‐like hydrogen‐bond energy, which is a 12‐10 potential with an angular term: where θ is the angle between the donor, hydrogen, and acceptor atoms, and C and D are empirical parameters. The power of 10 in the attractive term is intended to correct for the shorter separation than the sum of the van der Waals radii between the hydrogen bond donor and acceptor atoms.…”