Below is a CGI version of a MOPAC-like code for semiempirical quantum chemistry calculations. Several different NDDO-type Hamiltonians can be chosen for semiempirically solving the non-relativistic, time-independent, electronic Schrödinger equation at the X-Pol, FMO, or full QM levels. In addition, one may specify whether to use Mulliken or DPPC derived charges. Gradients can also be printed out, but are not entirely correct for this implementation of FMO. What is called "FMO" here is in fact the non-variationally optimized version of X-Pol (see reference from 1997 below). For all non-FMO calculations (including X-Pol), the gradients are correct. In this CGI version of the code, there is a limit of 200 atoms for full QM calculations, and a limit of 1200 atoms for FMO and X-Pol calculations. In addition there is a 30 second time limit for all types of calculations. Development of this software was partially supported by NIH grants GM46376 and RC1-GM091445 under Prof. Jiali Gao at the University of Minnesota.

Please cite use of this program as:
Michael J. M. Mazack, Web Interface for Semiempirical QM, FMO, & X-Pol; Version 1.0, http://mazack.org/cgi-bin/xpol.pl, 2013.

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• AM1: J. Am. Chem. Soc., 1985, 107 (13), 3902-3909
• PM3: J. Comput. Chem., 1989, 10 (2), 209-220
• FMO: J. Phys. Chem. B, 1997, 101 (4), 657-663 & Chem. Phys. Lett., 1999 313 (3-4), 701-706
• RM1: J. Comput. Chem., 2006, 27 (10), 1101-1111
• AM1-D & PM3-D: Phys. Chem. Chem. Phys., 2007, 9, 2362-2370
• PM6: J. Mol. Model., 2007, 13 (12), 1173-1213
• X-Pol: J. Chem. Phys., 2008, 128 (23), 234108
• PMO: J. Chem. Theory Comput., 2011, 7 (4), 857-867
• DPPC: J. Comput. Chem., 2011, 32 (10), 2127-2139
• PMOw: J. Chem. Phys., 2013, 139 (5), 054503