Journal Article 3 density-functional tight-binding Research Support, Non-U.S. Gov't 2 Research Support, U.S. Gov't, Non-P.H.S. 1 analytic derivative 1 double-helical structure 1 extended sampling 1 mehr ... fragment molecular orbital method 1 free energy simulation 1 helix-inversion 1 many-body interaction 1 molecular dynamics 1 molecular dynamics simulation 1 polarizable continuum model 1 potential of mean force 1 quantum mechanics/molecular mechanics 1 weniger ...