arXiv:1208.1928v2 [cond-mat.stat-mech] 12 Aug 2012 Quantum zero point effects using modified Nose-Hoover thermostats. Sriram Ganeshan 1 , R. Ramírez 2 , M. V. Fernández-Serra 1,a 1 Department of Physics and Astronomy, Stony Brook University, Stony Brook, New York 11794-3800, USA and 2 Instituto de Ciencia de Materiales de Madrid (ICMM), Consejo Superior de Investigaciones Científicas (CSIC), Campus de Cantoblanco, 28049 Madrid, Spain (Dated: August 14, 2012) Abstract Molecules like water have vibrational modes with zero point energy well above room temperature. As a consequence, classical molecular dynamics simulations of their liquids largely underestimate the kinetic energy of the ions, which translates into an underestimation of covalent interatomic dis- tances. Zero point effects can be recovered using path integral molecular dynamics simulations, but these are computationally expensive, making their combination with ab initio molecular dynamics simulations a challenge. As an alternative to path integral methods, from a computationally simple perspective, one would envision the design of a thermostat capable of equilibrating and maintaining the different vibrational modes at their corresponding zero point temperatures. Recently, Ceriotti et al. [Phys. Rev. Lett. 102, 020601 (2009)] introduced a framework to use a custom-tailored Langevin equation with correlated-noise that can be used to include quantum fluctuations in classi- cal molecular-dynamics simulations. Here we show that it is possible to use the generalized Langevin equation with suppressed noise in combination with Nose-Hoover thermostats to achieve an efficient zero-point temperature of independent modes. We apply this new thermostat to the molecular dy- namics of a flexible water force field. We address the question of whether thermostating each mode to its zero point temperature is enough to simulate nuclear quantum effects in water. PACS numbers: a) Electronic mail: maria.fernandez-serra@stonybrook.edu 1