Copyright © 2002–2012 by A. Miyoshi, Univ. Tokyo
GPOP - Quick Start step-1
[Top]   < Prev Step | Next Step >

GPOP - Quick Start step-1

  Followings are examples of the usage of GPOP tools for examination of intramolecular rotation etc.

Preparation

  1. Build GPOP from source files or unpack pre-built binaries for Windows according to the instructions in Installation section.
  2. Set PATH to the directory where GPOP executables reside.   Then, change directory to the gpop/sample.
  3. Alternatively, if you found any difficulty in setting PATH, copy all GPOP execultables (in gpop-win32-binary) and all sample files (in gpop/sample) to the current directory.

Pre-processing

  1. Execute gpop1scf for etp500.log by typing:
    gpop1scf etp500
  2. Files etp500.gpo and etp500.mod (or etp500_.mod) must have been created in the current directory.
  3. The file, etp500.gpo, is a GPOP format file containing essential results extracted from etp500.log. A GPOP format file is an ASCII text file and may be viewed with text editors. This file only may be usefull for some purposes: for example, the value of SCFenergy key in jobInfos block is the final SCF/DFT energy at optimized geometry.

Viewing normal mode vibrations by FreeWheel

(Skip this part if you are not using FreeWheel viewer.)
  1. Execute gpop5vib as;
    gpop5vib etp500
  2. Files named etp500_mnnn.log are generated. These files show animation of nnn-th vibrational modes when opend by FreeWheel software on Windows.

Calculation of properties of an intramolecular rotation

  1. Execute gpop6irt as;
    gpop6irt etp500 8-9 1-@
  2. Calculation is made for intramolecular rotation around C[1]–O[8] bond of the ethyl peroxy radical shown below.
  3. The properties of the intramolecular rotation specified in the command line are printed to the standard output as follows:
    base file name: etp500
    moiety-1: 8-9
    moiety-2: 1-2-3-4-5-6-7
    two moieties are whole molecule.
    dihedral angle between moieties 1 and 2: 71.4081
    [moiety-1]
        appI[amuA2]: 24.05850766
        appB[cm-1]: 0.70069305
     --- symmetric top ---
     symRedI[amuA2]: 6.66957233
     symRedB[cm-1]: 2.52754274
     --- asymmetric top ---
     asmRedI[amuA2]: 7.46994390
     asmRedB[cm-1]: 2.25672767
    [moiety-2]
        appI[amuA2]: 37.50552344
        appB[cm-1]: 0.44947057
     --- symmetric top ---
     symRedI[amuA2]: -4.75414496
     symRedB[cm-1]: -3.54588033
     --- asymmetric top ---
     asmRedI[amuA2]: 7.46994389
     asmRedB[cm-1]: 2.25672767
    [most resembling vibrations]
     mode-001: 0.99820037
     mode-010: 0.53138804
     mode-004: 0.46718380
     mode-009: 0.29262286
     mode-020: 0.24449702

  4. In most cases, the required results can be found in the last of [moiety-1] section. The reduced moment of inertia for rotation around C–O bond is 7.470 amu Å2, or the corresponding rotational constant is 2.257 cm–1. Also the last [most resembling vibarations] section indicate that the rotaion around C–O bond well resembles the vibrational mode #1.

[Top]   < Prev Step | Next Step >