Volume 2 Chapter 7 Numeric Sub-menu *TOLERANCE

Function

*TOLERANCE is used to test for a specified value or range of values of the bonding tolerance.

CSD Contents

Two atoms P and Q are considered to be bonded if:

rP + rQ - tol .LE. d(P-Q) .LE. rP + rQ + tol

where

rP, rQ
- are the elemental radii of atoms P and Q
d(P-Q)
- is the distance between atoms P and Q
tol
- is the bonding tolerance.

The default value for the bonding tolerance is 0.4Å.

Normally you will not need to use this test but an example is shown below.

Graphics QUEST3D Procedure

Select *TOLERANCE from the NUMERIC sub-menu and respond to the standard numeric prompts.

Basic QUEST Procedure

Ex.

T1  *TOLE  .GT.  0.5

This will register hits for all entries having a value of the bonding tolerance greater than 0.5Å.

In each such entry there must be at least one elemental pair P,Q for which the minimum bond distance dmin and maximum bond distance dmax span a range of more than 1Å.

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Volume 2 Chapter 7 Numeric Sub-menu *YEAR .