Hi all, In SCC-DFTB,when calculate the foce in MD, why there is no need of gradient of the charge fluctuation to the nuclear displacement? gxaaas -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://www.dftb-plus.info/pipermail/dftb-plus-user/attachments/20120329/8c88c104/attachment.html>