{"oa_version":"Preprint","issue":"22","scopus_import":"1","quality_controlled":"1","title":"Non-equilibrium simulations of thermally induced electric fields in water","main_file_link":[{"url":"https://arxiv.org/abs/1602.02734","open_access":"1"}],"language":[{"iso":"eng"}],"intvolume":" 144","date_published":"2016-06-10T00:00:00Z","day":"10","year":"2016","publisher":"American Institute of Physics","article_type":"original","keyword":["physical and theoretical chemistry","general physics and astronomy"],"pmid":1,"abstract":[{"lang":"eng","text":"Using non-equilibrium molecular dynamics simulations, it has been recently demonstrated that water molecules align in response to an imposed temperature gradient, resulting in an effective electric field. Here, we investigate how thermally induced fields depend on the underlying treatment of long-ranged interactions. For the short-ranged Wolf method and Ewald summation, we find the peak strength of the field to range between 2 × 107 and 5 × 107 V/m for a temperature gradient of 5.2 K/Å. Our value for the Wolf method is therefore an order of magnitude lower than the literature value [J. A. Armstrong and F. Bresme, J. Chem. Phys. 139, 014504 (2013); J. Armstrong et al., J. Chem. Phys. 143, 036101 (2015)]. We show that this discrepancy can be traced back to the use of an incorrect kernel in the calculation of the electrostatic field. More seriously, we find that the Wolf method fails to predict correct molecular orientations, resulting in dipole densities with opposite sign to those computed using Ewald summation. By considering two different multipole expansions, we show that, for inhomogeneous polarisations, the quadrupole contribution can be significant and even outweigh the dipole contribution to the field. Finally, we propose a more accurate way of calculating the electrostatic potential and the field. In particular, we show that averaging the microscopic field analytically to obtain the macroscopic Maxwell field reduces the error bars by up to an order of magnitude. As a consequence, the simulation times required to reach a given statistical accuracy decrease by up to two orders of magnitude."}],"article_number":"224102","publication":"The Journal of Chemical Physics","publication_status":"published","_id":"10380","doi":"10.1063/1.4953036","author":[{"last_name":"Wirnsberger","full_name":"Wirnsberger, P.","first_name":"P."},{"first_name":"D.","full_name":"Fijan, D.","last_name":"Fijan"},{"id":"bf63d406-f056-11eb-b41d-f263a6566d8b","last_name":"Šarić","orcid":"0000-0002-7854-2139","first_name":"Anđela","full_name":"Šarić, Anđela"},{"last_name":"Neumann","first_name":"M.","full_name":"Neumann, M."},{"last_name":"Dellago","first_name":"C.","full_name":"Dellago, C."},{"last_name":"Frenkel","full_name":"Frenkel, D.","first_name":"D."}],"publication_identifier":{"eissn":["1089-7690"],"issn":["0021-9606"]},"extern":"1","type":"journal_article","date_updated":"2021-11-29T13:09:08Z","volume":144,"oa":1,"user_id":"8b945eb4-e2f2-11eb-945a-df72226e66a9","external_id":{"arxiv":["1602.02734"],"pmid":["27305991"]},"status":"public","month":"06","date_created":"2021-11-29T11:08:52Z","citation":{"ista":"Wirnsberger P, Fijan D, Šarić A, Neumann M, Dellago C, Frenkel D. 2016. Non-equilibrium simulations of thermally induced electric fields in water. The Journal of Chemical Physics. 144(22), 224102.","chicago":"Wirnsberger, P., D. Fijan, Anđela Šarić, M. Neumann, C. Dellago, and D. Frenkel. “Non-Equilibrium Simulations of Thermally Induced Electric Fields in Water.” The Journal of Chemical Physics. American Institute of Physics, 2016. https://doi.org/10.1063/1.4953036.","apa":"Wirnsberger, P., Fijan, D., Šarić, A., Neumann, M., Dellago, C., & Frenkel, D. (2016). Non-equilibrium simulations of thermally induced electric fields in water. The Journal of Chemical Physics. American Institute of Physics. https://doi.org/10.1063/1.4953036","short":"P. Wirnsberger, D. Fijan, A. Šarić, M. Neumann, C. Dellago, D. Frenkel, The Journal of Chemical Physics 144 (2016).","ama":"Wirnsberger P, Fijan D, Šarić A, Neumann M, Dellago C, Frenkel D. Non-equilibrium simulations of thermally induced electric fields in water. The Journal of Chemical Physics. 2016;144(22). doi:10.1063/1.4953036","mla":"Wirnsberger, P., et al. “Non-Equilibrium Simulations of Thermally Induced Electric Fields in Water.” The Journal of Chemical Physics, vol. 144, no. 22, 224102, American Institute of Physics, 2016, doi:10.1063/1.4953036.","ieee":"P. Wirnsberger, D. Fijan, A. Šarić, M. Neumann, C. Dellago, and D. Frenkel, “Non-equilibrium simulations of thermally induced electric fields in water,” The Journal of Chemical Physics, vol. 144, no. 22. American Institute of Physics, 2016."},"acknowledgement":"The authors should like to dedicate this paper to the memory of Simon de Leeuw, who was a pioneer in the calculation of Coulomb effects in simulations. P.W. would like to thank the Austrian Academy of Sciences for financial support through a DOC Fellowship, and for covering the travel expenses for the CECAM workshop in Zaragoza in May 2015, where these results were first presented. P.W. would also like to thank Chao Zhang for pointing out the equivalence of the two expressions for the electric field discussed in Sec. VI D, Michiel Sprik for emphasising the importance of the quadrupole contribution in experimental studies of interfacial systems, as well as Aleks Reinhardt and other members of the Frenkel and Dellago groups for their advice. We further acknowledge support from the Federation of Austrian Industry (IV) Carinthia (P.W.), the University of Zagreb and Erasmus SMP (D. Fijan), the Human Frontier Science Program and Emmanuel College (A.Š.), the Austrian Science Fund FWF within the SFB Vicom project F41 (C.D.), and the Engineering and Physical Sciences Research Council Programme Grant No. EP/I001352/1 (D.F.). Additional data related to this publication are available at the University of Cambridge data repository (http://dx.doi.org/10.17863/CAM.118).","article_processing_charge":"No"}