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Updated: Aug 4, 2026

Computation of Atmospheric Concentrations of Molecular Clusters from ab initio Thermochemistry
Published on: April 8, 2020
Optimization of parameters for semiempirical methods IV: extension of MNDO, AM1, and PM3 to more main group elements
1Stewart Computational Chemistry, 15210 Paddington Circle, Colorado Springs CO 80921, USA. Jstewart@us.fujitsu.com
Abstract:
The NDDO semiempirical methods MNDO, AM1, and PM3 have been extended to all the remaining non-radioactive elements of the main group, excluding the noble gases. Most of the new elements are of Groups I and II. 44 sets of parameters are presented for the following methods and elements. MNDO: Na, Mg, K, Ca, Ga, As, Se, Rb, Sr, In, Sb, Te, Cs, Ba, Tl, and Bi; AM1: Li, Be, Na, Mg, K, Ca, Ga, As, Se, Rb, Sr, In, Sn, Sb, Te, Cs, Ba, Tl, Pb, and Bi; PM3: B, Na, K, Ca, Rb, Sr, Cs, and Ba. Average errors are presented for heats of formation, molecular geometries, etc.
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