Next-Generation Ab-initio Force Field Development

Molecular simulation is an essential tool for interpreting and predicting the structure, thermodynamics, and dynamics of chemical and biochemical systems. The fundamental inputs into these simulations are the intra- and intermolecular force fields, which provide simple and computationally efficient descriptions of molecular interactions. (By force field, we mean a set of parameters and equations used to model the potential energy surface of a sytem). Consequently, the predictive and explanatory power of molecular simulations depends on the fidelity of the force field to the underlying (exact) potential energy surface. Because the development of high-quality force fields is so essential to accurate molecular simulation, a major focus of our group is on improving the force field development process, with a particular emphasis on studying intermolecular interactions. Our methodology is centered on "physically-motivated" force field development, with the hypothesis that we can craft highly accurate, broadly applicable, and easy-to-develop intermolecular force fields by requiring that the parameters and equations used in our models are closely derived from the underlying physics of intermolecular interactions. (See Schmidt, 2015VanVleet, 2016; McDaniel, 2014; McDaniel, 2013; Yu, 2011 for more details)



Using our "physically-motivated" force field development methodology (here termed Slater-ISA), we are able to generate force fields that are both highly accurate (as demonstrated by the good reproduction of high-level ab initio benchmark energies computed from SAPT) and that are insensitive to the details of force field parameterization, especially compared to previous approaches (here termed Born-Mayer-IP). See VanVleet, 2016 for original figure and details.


In the process of improving intermolecular force fields, our group has simultaneously sought to apply our methodology to a variety of real-world applications, ranging from gas separation in metal-organic frameworks (see McDaniel, 2015McDaniel, 2012Yu, 2011) to structural and dynamic properties of ionic liquids (see McDaniel, 2016; Son, 2016) and neat organic liquids (see McDaniel, 2013). Future applications of our force fields will include MOF nucleation and growth as well as biomolecular simulation.


CO2 gas adsorption isotherms at 298 K for selected metal-organic frameworks (MOFs). Simulation results (symbols) are compared with corresponding experimental values (lines). See Schmidt, 2015 for original figure and details.


By combining methodological advances with timely applications to problems in chemical and materials science, we hope work in our group will significantly broaden and improve the scope of molecular simulation.


1) Schmidt J.R, Yu K, McDaniel J.  2015.  Transferable Next-Generation Force Fields from Simple Liquids to Complex Materials. Accounts of Chemical Research. 48(3):548–556.  

2) Van Vleet MJ, Misquitta AJ, Stone AJ, Schmidt J.R.  2016.  Beyond Born–Mayer: Improved Models for Short-Range Repulsion in ab Initio Force Fields. J. Chem. Theory Comput. Article ASAP

3) McDaniel J, Schmidt J.R.  2014.  First-Principles Many-Body Force Fields from the Gas Phase to Liquid: A “Universal” Approach. The Journal of Physical Chemistry B. 118(28):8042–8053.

4) McDaniel J, Schmidt J.R.  2013.  Physically-Motivated Force Fields from Symmetry-Adapted Perturbation Theory. The Journal of Physical Chemistry A. 117(10):2053–2066.

5)Yu K, Schmidt J.R.  2011.  Elucidating the Crystal Face- and Hydration-Dependent Catalytic Activity of Hydrotalcites in Biodiesel Production. The Journal of Physical Chemistry C. 115(5):1887-1898.

6) McDaniel J, Li S, Tylianakis E, Snurr RQ, Schmidt J.R.  2015.  Evaluation of Force Field Performance for High-Throughput Screening of Gas Uptake in Metal-Organic Frameworks. Journal of Physical Chemistry C. 119(6):3143–3152.

7) McDaniel J, Schmidt J.R.  2012.  Robust, Transferable, and Physically Motivated Force Fields for Gas Adsorption in Functionalized Zeolitic Imidazolate Frameworks. The Journal of Physical Chemistry C. 116(26):14031-39.

8) McDaniel J, Choi E, Son C-Y, Schmidt J.R, Yethiraj A.  2016.  Conformational and Dynamic Properties of Poly(ethylene oxide) in an Ionic Liquid: Development and Implementation of a First-Principles Force Field. Journal of Physical Chemistry B. 120(1):231-243. 

9) Son CYun, McDaniel JGatten, Schmidt JR, Cui Q, Yethiraj A.  2016.  First Principles United Atom Force Field for the Ionic Liquid [BMIM][BF4] : An Alternative to Charge Scaling. J. Phys. Chem B. 120(14):3560-3568.