modified on 10 August 2010 at 14:19 ••• 5,984 views

Qmmm method

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method   [method1]  [method2]  [method3]

This directive controls which optimization algorithm will be used for the regions as defined by regions directive. The allowed values are "bfgs" aka driver, "lbfgs" limited memory version of quasi-newton, and "sd" simple steepest descent algorithm. The "bfgs" is the most expensive algorithm and is not recomended for more than 100 particles (this essentially restricts its usage only to "qm" or "qmlink" regions). The "lbfgs" algorithm is recomended for both small and large regions and should be used whenever is possible (in many cases it outperforms "bfgs"). Finally "sd" the most ineficient and slow way to optimize regions, yet it is the only option available for the optimization of solvent regions. The default is to assign "sd" to optimization involving solvent region (if any), and "lbfgs" to all others.