Analytical energy derivatives and normal modes in force fields employing lone-pair pseudoatoms
✍ Scribed by Marvin Waldman; Brian B. Masek
- Publisher
- John Wiley and Sons
- Year
- 1989
- Tongue
- English
- Weight
- 398 KB
- Volume
- 10
- Category
- Article
- ISSN
- 0192-8651
No coin nor oath required. For personal study only.
✦ Synopsis
Formulas are derived for analytical first and second energy derivatives with respect to nuclear coordinates in molecular mechanics force fields employing lone-pair pseudoatoms. These derivatives may fwther be used for the calculation of normal modes and vibrational frequencies while properly accounting for the presence of pseudoatoms. The equations are applied using the MM2 force field to calculate the vibrational spectrum of methanol to illustrate the applicability of the method. The results are compared to both experiment and a numerical approximation in which small masses are assigned to the lonepair pseudoatoms.