<div dir="ltr">Hello PWSCF Forum,<div><br></div><div>First time caller, long time listener. I am working with a group using Quantum Espresso to extract two-body interatomic potentials (IP) for an ionic crystal system (metal borides, to be exact). These potentials will then be put to use in molecular dynamics software (DL-Poly). From my understanding with MD, most software nowadays typically employs electrostatics as a separate potential from the heteronuclear IP's. In order to (1) get the correct heteronuclear IP and (2) simulate a "realistic" electrostatic environment in MD, it would be best to have the right point charges for the system. After browsing through the forum and user guides, I noticed that PP.x (plot_num = 0) has the ability to output charge density distributions. The output I received had, depending on which plot type used, five or six columns, of which I am assuming are related to charge values on a grid. Is this correct, and if so, how do I find the corresponding grid? </div>
<div><br></div><div>My idea was to integrate the charge density in a Wigner-Seitz cell around each ion to get point charges for use in electrostatics. I'm not sure if there's a better way to accomplish this goal; this was my attempt. I apologize if I have overlooked a thread, please notify me so. Thanks in advance and I look forward to your advice.</div>
<div><br></div><div>P.S. The output I received for a model system is given below for a specified "filplot", plot_num = 0.<br><div><br></div><div><div> </div>
<div> 72 72 72 72 72 72 4 2</div><div> 1 7.00000000 0.00000000 0.00000000 0.00000000 0.00000000 0.00000000</div><div> 1191.5371196339 12.0000000000 80.0000000000 0</div>
<div> 1 La 11.00</div><div> 2 B 3.00</div><div> 1 0.000000000 0.000000000 0.000000000 1</div><div> 2 0.000000000 0.500000000 0.500000000 2</div><div> 3 0.500000000 0.000000000 0.500000000 2</div>
<div> 4 0.500000000 0.500000000 0.000000000 2</div><div> 3.434814311E-01 3.431749032E-01 3.422272391E-01 3.405249826E-01 3.378906730E-01</div><div> 3.341004832E-01 3.288993448E-01 3.220354913E-01 3.132873382E-01 3.024951442E-01</div>
<div> 2.895821234E-01 2.745777240E-01 2.576219405E-01 2.389737928E-01 2.190001080E-01</div><div> 1.981636489E-01 1.769910061E-01 1.560378501E-01 1.358452121E-01 1.168975755E-01</div><div> 9.959052347E-02 8.420256729E-02 7.088392771E-02 5.965905586E-02 5.043519819E-02</div>
<div>..... more values</div><div><br></div>-- <br>Kevin Schmidt<div><i>Chemical Engineering Department</i></div><div><i>University of Nevada, Reno, USA</i></div></div></div></div>