@article {43241,
	title = {Non-covalent interactions in extended systems described by the effective fragment potential method: theory and application to nucleobase oligomers},
	journal = {Journal of Physical Chemistry A},
	volume = {114},
	year = {2010},
	month = {NOV},
	abstract = {The implementation of the effective fragment potential (EFP) method within the Q-CHEM electronic structure package is presented. The EFP method is used to study noncovalent π-π and hydrogen-bonding interactions in DNA strands. Since EFP is a computationally inexpensive alternative to high-level ab initio calculations, it is possible to go beyond the dimers of nucleic acid bases and to investigate the asymptotic behavior of different components of the total interaction energy. The calculations demonstrated that the dispersion energy is a leading component in π-stacked oligomers of all sizes. Exchange-repulsion energy also plays an important role. The contribution of polarization is small in these systems, whereas the magnitude of electrostatics varies. Pairwise fragment interactions (i.e., the sum of dimer binding energies) were found to be a good approximation for the oligomer energy.},
	author = {Ghosh, Debashree and Kosenkov, Dmytro and Vanovschi, Vitalii and Williams, Christopher F. and Herbert, John M. and Gordon, Mark S. and Schmidt, Michael W. and Slipchenko, Lyudmila V. and Krylov, Anna I.}
}
@article { ISI:000317082100007,
	title = {Effective fragment potential method in Q-CHEM: a guide for users and developers},
	journal = {Journal of Computational Chemistry},
	volume = {34},
	number = {12},
	year = {2013},
	month = {MAY},
	pages = {1060-1070},
	publisher = {WILEY-BLACKWELL},
	address = {111 RIVER ST, HOBOKEN 07030-5774, NJ USA},
	abstract = {<p>A detailed description of the implementation of the effective fragment potential (EFP) method in the Q-CHEM electronic structure package is presented. The Q-CHEM implementation interfaces EFP with standard quantum mechanical (QM) methods such as HartreeFock, density functional theory, perturbation theory, and coupled-cluster methods, as well as with methods for electronically excited and open-shell species, for example, configuration interaction, time-dependent density functional theory, and equation-of-motion coupled-cluster models. In addition to the QM/EFP functionality, a fragment-only feature is also available (when the system is described by effective fragments only). To aid further developments of the EFP methodology, a detailed description of the C++ classes and EFP module{\textquoteright}s workflow is presented. The EFP input structure and EFP job options are described. To assist setting up and performing EFP calculations, a collection of Perl service scripts is provided. The precomputed EFP parameters for standard fragments such as common solvents are stored in Q-CHEM{\textquoteright}s auxiliary library; they can be easily invoked, similar to specifying standard basis sets. The instructions for generating user-defined EFP parameters are given. Fragments positions can be specified by their center of mass coordinates and Euler angles. The interface with the IQMOL and WEBMO software is also described. (c) 2013 Wiley Periodicals, Inc.</p>},
	keywords = {effective fragment potential, EFP library, hybrid QM, IQMOL, MM, modular code, nonempirical force field, Q-CHEM, WEBMO},
	issn = {0192-8651},
	doi = {10.1002/jcc.23223},
	author = {Ghosh, Debashree and Kosenkov, Dmytro and Vanovschi, Vitalii and Flick, Joanna and Kaliman, Ilya and Shao, Yihan and Gilbert, Andrew T. B. and Krylov, Anna I. and Slipchenko, Lyudmila V.}
}
