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Geometry Optimization with Constraints

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Author Post
Member
Registered: Nov 2012
Posts: 11
Dear Forum,

I am trying to perform a number geometry optimizations with a bond length constraint (for a potential energy scan). However, often I get the following error:

Minimum Search - Taking P-RFO Step
Searching for Lamda that Maximizes Along the Constraint modes Only
Value Taken Lamda = 5.59700831

********************************************
** ERROR IN DETERMINING Lamda IN CONFormD **
********************************************


When this error occurs the algorithm continues but does not produce any change in the nuclear coordinates at subsequent steps, viz:

New Cartesian Coordinates Obtained by Inverse Iteration

Displacement from previous Coordinates is: 0.000000


This then means the optimization eventually runs out of steps and crashes.
Has anyone had experience with the constraint algorithm and knows what is going on here and could perhaps suggest a solution?

Geoff
Member
Registered: Jan 2017
Posts: 1
Hi Geoff,

I met the same problem as you. Did you figure out the problem?

Yang

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