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DQΦpac 21

A Diabatization Program for Performing DQ and DQΦ Diabatization

Chad E. Hoyer, Kelsey A. Parker, Zoltan Varga, Laura Gagliardi, and Donald G. Truhlar

Department of Chemistry and Minnesota Supercomputing Institute
University of Minnesota, Minneapolis, Minnesota 55455

DQΦpac status

Most recent version: 21
Date of most recent version: July 21, 2021
Date of most recent manual update: July 21, 2021


DQΦpac is a Fortran 90 diabatization program. It has the following capabilities:

  • DQΦpac can be used for property based diabatization by Boys localization, quadrupole moment, quadrupole, electrostatic potential, two-electron orbital angular momentum, and their combinations.
  • The user must supply adiabatic potential energies and properties from calculations carried out with the Molpro or Q-Chem electronic structure package (which must be obtained separately). The code returns the adiabatic-to-diabatic transformation matrix and diabatic potential energy matrix as output.
  • Given a set of quadrupole moment integrals at an origin, the program can compute quadrupole integrals at any other origin.

Test input and output for DQΦpac can be found in the "testruns" directory.

DQΦpac features

One can diabatize at a single geometry using user-supplied potential energies and the dipole, quadrupole, electrostatic potential, and two-electron orbital angular momentum molecular integrals (the N-electron integrals, not the 1-electron integrals). If one only uses the dipole, the method is known as Boys localized diabatization. If the dipole and quadrupole are used, the method is known as dipole-quadrupole diabatization (DQ). If the dipole, quadrupole, and electrostatic potential are used, the method is called dipole-quadrupole-electrostatic-potential diabatization (DQΦ). If the dipole and electrostatic potential are used, the method is referred to as dipole-electrostatic-potential diabatization (DΦ), but it is considered specific case of DQΦ diabatization. Only using the quadrupole (Q) or electrostatic potential (Φ) are also considered specific cases of DQΦ diabatization. The two-electron orbital angular momentum (L2) also can be combined with the DQΦ to give DQΦL2. The combinations DL2, QL2, DQL2, etc. are considered as special cases of DQΦL2.

  • Diabatization methods
    1. Boys localized diabatization [ J. Chem. Phys, 129, 244101 (2008)].
    2. dipole-quadrupole diabatization (DQ) [ J. Chem. Phys, 141, 114104 (2014)].
    3. dipole-quadrupole-electrostatic-potential diabatization (DQΦ) [J. Chem. Phys, 144, 194101 (2016)].
    4. dipole-quadrupole-electrostatic-potential-two-electron-orbital-angular-momentum diabatization (DQΦL2).

DQΦpac platform compatibility

The DQΦ code has been tested successfully on the following platforms:




Itasca Linux Cluster

CentOS Linux

GCC Compiler 4.4.7


Users' Manual

Licensing and downloading:

DQΦpac - version 21 is licensed under the Apache License, Version 2.0.
The manual of DQΦpac - version 21 is licensed under CC-BY-4.0.

Publications of results obtained with the DQΦpac - version 21 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 DQΦpac - version 21 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 Oct. 20, 2022
Updated by:  Software Manager