Volume 123, Issue 4, 22 July 2005
Index of content:
123(2005); http://dx.doi.org/10.1063/1.1978870View Description Hide Description
For the first time the rotational spectrum of the molecular anion has been observed by microwave spectroscopy. has been produced both by a positive and negative glow discharge; by investigating the Doppler shift in both cases, the unshifted frequency of the rotational transition has been derived. This allowed us to improve the value of the ground-staterotational constant:. In order to assess that a negative ion has really been observed, the cation has been produced and investigated in the same experimental conditions.
123(2005); http://dx.doi.org/10.1063/1.1990113View Description Hide Description
We have developed a dual-topology/dual-coordinate free-energy simulation method for use with a QM/MM force field. By combining two parallel processes into one alchemical process, we are able to compute the double free-energy difference within a single simulation, which eliminates half of the expensive quantum-mechanical simulation in general. The method has been tested in computing the solvation free-energy differences of several molecular pairs and shows close agreement with experimental results.