MOLSCAT, Version 14

Jeremy M. Hutson

Department of Chemistry, University of Durham, Science Laboratories, South Road, Durham, DH1 3LE, England

E-mail: J.M.Hutson@durham.ac.uk

Sheldon Green (deceased)

NASA Goddard Space Flight Center, Institute for Space Studies, 2880 Broadway, New York, NY 10025, U.S.A.

MOLSCAT is a general-purpose package for performing quantum nonreactive molecular scattering calculations. It is written in near-standard FORTRAN 77, and runs on (among others) DEC VAX, DEC Ultrix, IBM mainframes, IBM RS/6000, Sun Sparc, Intel iPSC and CRAY computers. This manual describes the capabilities and modes of use of the program, and explains the input data required.

Publications resulting from use of MOLSCAT should cite it as described in Section 1.5 of this documentation.

JMH would be grateful to be informed of any bugs you encounter, either in MOLSCAT or in this documentation.

A tutorial on input data is also available which is designed to help new users of the MOLSCAT code. It walks through simple standard cases, providing examples of input decks and user-supplied potential routines which can actually be run; the output from such runs should illustrate the purpose and effect of various options.

Table of Contents

1. Introduction

• 1.1 Input data format
• 1.2 Collision types
• 1.3 Propagators
• 1.4 Important changes in version 14
• 1.5 Acknowledging use of MOLSCAT

2. NAMELIST block &INPUT

• 2.1 General purpose variables
• 2.2 Print level control
• 2.3 Angular momentum
• 2.4 Scattering energies
• 2.5 S-matrix output file
• 2.6 Partial cross section output file
• 2.7 Total cross section output file
• 2.8 Propagator scratch file
• 2.9 Pressure broadening calculations
• 2.10 Characterising scattering resonances
• 2.11 Surface scattering calculations
• 2.12 Control of propagators
  • Units of length
  • Range of integration
  • Step size
  • DeVogelaere propagator
  • R-matrix propagator
  • Hybrid log-derivative/VIVS propagator
  • WKB propagator

3. NAMELIST block &BASIS

• 3.1 ITYP = 1
• 3.2 ITYP = 2
• 3.3 ITYP = 3
• 3.4 ITYP = 4
• 3.5 ITYP = 5
• 3.6 ITYP = 6
• 3.7 ITYP = 7
• 3.8 ITYP = 8
• 3.9 ITYP = 9
• 3.10 Decoupling approximations

4. NAMELIST block &POTL

• 4.1 Exponentials and inverse powers
• 4.2 The VSTAR mechanism
• 4.3 The VRTP mechanism

5. User-supplied POTENL routines

• 5.1 Initialisation
• 5.2 Evaluation

6. NAMELIST block &CONV

7. Array dimensioning

8. COMMON blocks

9. Subroutines of the MOLSCAT system

10. Machine-dependent features

• 10.1 Main program
• 10.2 NAMELIST
• 10.3 Integer length
• 10.4 Date and time routines
• 10.5 CPU time routines
• 10.6 Floating point underflow
• 10.7 Linear algebra
• 10.8 File handling

11. References