EHT Home Page


April 2000

EHT 1.0


A program for Extended Hueckel Theory by

Tiqing Liu and Donald G. Truhlar
Department of Chemistry and Supercomputing Institute
University of Minnesota, Minneapolis, Minnesota 55455


EHT 1.0 description:

EHT is a FORTRAN 77 program for using extended Hueckel theory to calculate the energy of a system, analytical first derivatives of the energy with respect to the atomic Cartesian coordinates, and the Mulliken atomic charges. The calculations include overlap in the secular equation, and the Hamiltonian matrix is evaluated by the Wolfsberg-Helmholz approximation. No core repulsion term is included. The basis functions are Slater-type orbitals (STOs). In this program, d subshells are described by a contracted double zeta STO basis, and s and p subshells are each described by a single zeta STO basis. Overlap integrals are evaluated by the method of Jones and Weatherford. The program contains parameters for the following elements: H-Cs (noble gas elements are excluded), and La-Sm. Parameters are taken from QCPE Program 571 except for Ag; the Ag parameters are from Anderson, McDevitt, and Urbach (see reference in Section 2).

EHT 1.0 Manual:

  1. text format

Licensing and downloading:

EHT - version 1.0 is licensed under the Apache License, Version 2.0.
The manual of EHT - version 1.0 is licensed under CC-BY-4.0.

Publications of results obtained with the EHT - version 1.0 software should cite the program and/or the article describing the program.

No guarantee is made that this software is bug-free or suitable for specific applications, and no liability is accepted for any limitations in the mathematical methods and algorithms used within. No consulting or maintenance services are guaranteed or implied.

The use of the EHT - version 1.0 implies acceptance of the terms of the licenses. The software may be downloaded here.

Links to other pages of interest:


This document last modified on August 8, 2021
Updated by:  Software Manager