PROGRAM MOLVOL : MOLecular VOLume determination

SUBROUTINE MOLVOL

volume.f - volume determination code

Author: Lawrence R. Dodd Doros N. Theodorou Doros N. Theodorou
Maintainer: Lawrence R. Dodd
Created: March 21, 1990
Version: 2.0
Date: 1994/07/22 15:45:51
Keywords: volume and area determination
Time-stamp: <94/07/22 11:02:23 dodd>
Copyright (c) 1990, 1991, 1992, 1993, 1994 by Lawrence R. Dodd and Doros N. Theodorou.

Plane Sphere Intersections

This program will find the total and individual volume and exposed surface area of an arbitrary collection of spheres of arbitrary radii cut by an arbitrary collection of planes analytically by analyzing the plane/sphere intersections.

Algorithm by: Doros N. Theodorou and Lawrence R. Dodd Coded by: L.R. Dodd

Created on: March 21, 1990 Phase 1 Completed on: March 23, 1990 Phase 2 Completed on: April 16, 1990 Phase 3 Completed on: May 17, 1990 Phase 4 Completed on: June 5, 1990 Phase 5 Completed on: July 26, 1990

Reference: "Analytical treatment of the volume and surface area of molecules formed by an arbitrary collection of unequal spheres intersected by planes" L.R. Dodd and D.N. Theodorou MOLECULAR PHYSICS, Volume 72, Number 6, 1313-1345, April 1991

Acknowlegement: LRD wishes to thank his mentor DNT for a stimulating and enjoyable post-doctoral experience.

General Notes On Program: This program has been written with an eye towards both efficiency and clarity. On a philosophical note, many believe that these ideals are mutually exclusive but in general they are not. There are, however, a few instances where one ideal has been given more prominence over the other. The comments in the program, together with the associated journal article, should help to explain any apparent logical leaps in the algorithm.

The program was intended to be used as a subroutine called repeatly by some main program. In this case the subroutine "VOLUME" is called by some main routine which has placed the necessary information in common block /Raw Data/. The answers are returned in common block /Volume Output/. I must apologize for the poor input/output for the program. For example, the area/volume of each sphere is not placed in /Volume Output/.

This program was developed on a Sun SPARCstation 330 using Sun FORTRAN 1.3.1 (all trademarks of Sun Microsystems, Inc.). We have used some of extensions to the ANSI standard including:

o long variable names (i.e., more than six characters)

  • variable names containing the characters '$' and '_'
  • END DO used in place of the CONTINUE statement
  • DO-WHILE used in place of IF-GOTO constructs
  • excessive number of continuation lines in some FORMATs
  • generic intrinsic function calls (e.g., SIN for DSIN)
  • IMPLICIT NONE statement (needed in development)

    The advantage of using non-standard FORTRAN is that it makes it C considerably easier to follow the flow of a program. There are no extraneous statement labels in this program that may have obscured the logic (not a single GOTO was used). The previews of the new F90 standard appear to adopt many of the features already implemented in VMS, Sun, Cray, and IBM FORTRAN. Note that this algorithm is completely parallelizable.

    Larry Dodd
    dodd@mycenae.cchem.berkeley.edu
    Department of Chemical Engineering
    ollege of Chemistry
    University of California at Berkeley
    Berkeley, California 94720-9989
    (415) 643-7691 (LRD)
    (415) 643-8523 (DNT)
    (415) 642-5927 (Lab)
    dodd@mycenae.cchem.berkeley.edu
    doros@mycenae.cchem.berkeley.edu

    Note: Plane_Ordering of common block /Debug/ is, as the name implies, for debugging purposes only as is routine ORDERING. The information contain therein is not necessary for solving the sphere plane problem but proved incredibly useful during program development.

    Dr. John Waite, e-mail: chem8@york.ac.uk
    The National Helleni rosen@cyclades.nrcps.ariadne-t.gr
    Research Foundation,
    Organic and Pharaceutical Institute, phone: ++30-1-7238958 (direct)
    Vas. Konstantinou 48, phone: ++30-1-7247913(secrtry.Mary)
    Athens 116-35, fax: ++30-1-7247913
    Greece
    or NCRS "Democritos", phone: ++30-1-6513112-5 X219
    c/o Dr. G.Kordas, e-mail john@john.nrcps.ariadne-t.gr
    Material Science Institute,
    Aghia Paraskevi,
    Attikis,
    Athens 153-10,
    Greece