10 Vibrational Analysis

The vibrational analysis routines are designed to provide the user a variety of analysis options as well as features designed to facilitate the interface to the analysis (see Analysis). The vibrational analysis and this documentation was written by Bernard R. Brooks who is presently (1990) at NIH.

To use the vibrational analysis, one must first execute then VIBRAN command. This enters a separate command parser which has its own set of commands. Control is returned to the top level of CONGEN with an END command.

In order to process commands with the vibrational analysis routines, The energy terms must all be defined, and the structure must be determined (see Energy Needs). At present, fixing constraints (see Fixed Atoms) SHAKE (see Shake Command), and images (see Images) are not supported.

Keywords used to define hydrogen bonds and nonbonded interactions may be included in the command that invokes VIBRAN.

• Syntax of Vibrational Analysis: Syntax of VIBRAN command and subcommands
• I/O in Vibrational Analysis: Read and write subcommands.
• Second Derivatives: Generation, storage, and uses of second derivatives
• Normal Modes: Modifications or use of normal modes
• Vibrational Manipulations: Manipulation of coordinates and modes
• Energy Surface Exploration: Exploration of the energy hypersurface