Boundary Adjustments (i)Selective deletion of 1e integrals
- L1: Delete integrals for which basis functions i or j are sited on the link atom L
use coupling=L1 with qm_theory=mndo
- found to be effective for semi-empirical wavefunctions
- difference in potential acting on nearby basis functions causes unphysical polarisation for ab-initio QM models
- L3: Delete integrals for which basis functions i and j are cited on the link atom and qA is the neighbouring MM atom (M1)
- less consistent results observed in practice †
† Classification from Antes and Thiel, in Combined Quantum Mechanical and Molecular Mechanical Methods, J. Gao and M. Thompson, eds. ACS Symp. Ser., Washington DC, 1998.