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IntroductionList of quantum chemistry code sitesPeriodicMolecularPseudopotentials/ECP/PAWFunctionalsOther DFT electronic structure sites Introduction The following is a list of sites that document various density-functional theory based electronic structure codes, both periodic and molecular, and atomic pseudopotential codes. This list is no way comprehensive, nor makes any representation of what the codes do,...

All AM05 pseudopotentials are generated using the Fritz-Haber Institute fhi98PP code: M. Fuchs and M. Scheffler, Comput. Phys. Commun. 119, 67 (1999)and either employ the Hamann type of norm-conserving pseudopotential, D.R. Hamann, Phys. Rev. B 40, 2980 (1989),or the Troullier/Martins type, N. Troullier and J.L. Martins, Phys. Rev. B 43, 1993...

This page provides a description of some of the analysis tools and utility codes available for use with Quest. The tool set for Quest is not extensive, not that well organized, but is actively being developed. The following describe the principal tools currently available in some form: Band structure - compute...

This page gives a description of the structure of atom files (potentials and basis sets) used in the DFT calculations. It is possible to construct atom files for atoms with pseudopotentials, all-electron atoms with bare-core potentials, and "floating" orbitals without any potentials. Pseudopotentials with non-local projectors up to l=2 are...

SeqQuest requires pseudopotentials and Gaussian basis sets for every atom type in a given calculation. These pseudopotentials are not generated within Quest itself: the Gaussian basis sets are atom- and potential-specific and must be provided. Quest accesses the pseudopotentials and associated basis sets it uses from atom files that have...

Quest is a general purpose electronic structure code based on density functional theory. It uses pseudpotentials and a high quality local orbital basis of contracted Gaussian functions in a linear combination of atomic orbitals (LCAO) approach to solve the Kohn-Sham equations fully self-consistently. This page gives a (very) brief description...

The band structure capability was developed by Arthur H. Edwards and Andrew C. Pineda (AFRL), who should be cited (unpublished) for any use of the band structure capability. Overview The band structure feature computes energies along lines connecting high symmetry points in the Brillouin zone for the standard Bravais lattices....

This band structure example and associated scripts was developed by Andrew C. Pineda (AFRL), Setting up the band structure calculation To set up a band structure calculation, first you do a single-point SeqQuest calculation, configuring the band structure calculation using the options specified in the band structure manual. The input file...

There have been three generations of codes implementing the method as of this date, and the publications in the following are segregated by which code was employed in the application. Peter Feibelman's original slab codeA massively parallel code by Mark Sears (with PAS)The current production code I. Feibelman's original slab...

All BLYP pseudopotentials are generated using the Fritz-Haber Institute fhi98PP code:M. Fuchs and M. Scheffler, Comput. Phys. Commun. 119, 67 (1999)and either employ the Hamann type of norm-conserving pseudopotential,D.R. Hamann, Phys. Rev. B 40, 2980 (1989),or the Troullier/Martins type,N. Troullier and J.L. Martins, Phys. Rev. B 43, 1993 (1991). Also,...

This page provides guidance and instructions for building an executable from the shipped code package. Often this will be as simple as unpacking the code, and then "make" or "make platform", but should rarely be much more complicated than that. Mostly, you will be visiting this page in the uncommon event...

IntroductionExamples:Example: A basic input fileHexagonal symmetries and BZ samplingPicking a density functional (and spin)Symmetry I: Point groupsScaling functions I: global scalingScaling functions II: direction-specificShift coordinatesSymmetry II: non-symmorphic groupsSCF parametersAtomic relaxationRelaxation parametersLattice coordinatesCalculations with strainCell optimizationAliasing atom typeslabeling atoms Introduction The purpose of this tutorial is to introduce the user to...

This page gives a description of input section that controls and modifies how a cell relaxation is done. The code does a fully general cell relaxation via stress-elimination, enforcing all user-specified symmetry, for 1D, 2D, and bulk 3D systems. The cell relaxation input section is optional; all the user need...

IntroductionPitfalls - it's not your usual molecular codeExamplesExample: A basic input file - the H atomPicking a density functional (and spin) - H atomSupercell size - H2 moleculeMultiple atoms and types - C6H6 benzeneSupercell shape - C6H6Scaling coordinates - C4H4Aliasing atom types - O(CH3)2Shifting the origin - O(CH3)2SCF parameters - C4H4Structural...

This page gives a description of the "command options" input section, which controls the global operation and actions of the code. This section begins an input file. It tells the code what it will do (scf, forces, relaxation, etc), how it will do it (with or without blas/3 libraries, eigensolver...

This page provides guidance and information for use in development in the Quest Project. Programming Style ManualDescription of coding conventions used in the Quest codeQuest Files Reference ManualDescription of the contents of working files used in a Quest calculation.Build GuideHow to install and build an executableJob ManualDescription of how to...

Quest is a general purpose electronic structure code based on density functional theory. It uses pseudpotentials and a high quality local orbital basis of contracted Gaussian functions in a linear combination of atomic orbitals (LCAO) approach to solve the Kohn-Sham equations fully self-consistently. Feature summary (Version 2.66) Basic functionalityGeneral purpose...

Quest generates many files in the course of a calculation. The purpose of this page is to summarize the more important of these. The convention Quest adopts is to use a common prefix (currently chosen to be "lcao", but can be trivially changed), and alter the suffix for each file,...

Overview This page gives a description of the input section that controls and modifies how an atomic geometry relaxation is done. The code does a full geometry relaxation via force-elimination, enforcing all user-specified symmetry, and respecting all constraints specified by the user in this section. The geometry relaxation input section...

Quest uses a structured input file divided into sections of related data. The input is designed to be self-documenting. The input is keyword-driven (left-justified) followed by lines with (mostly) free-format data. Only the first few characters of a keyword line are significant; the remainder of a line can be used...

A Quest calculation requires an input file called "lcao.in", needs to locate atom files specified in the input file, generates an output file to standard output (which can be redirected), and generates a number of local files in the course of execution that can possible be very sizeable. Only one Quest calculation...

All LDA atom file (pseudopotential and associated basis sets) are developed by Peter A. Schultz (Sandia), P.A. Schultz, unpublished. All LDA potentials are Hamann type norm-conserving pseudopotentials,D.R. Hamann, Phys. Rev. B 40, 2980 (1989),except for N,C,O,F,Ni,Cu,Zn, and Ga(d10) which use the Troullier/Martins type,N. Troullier and J.L. Martins, Phys. Rev. B 43,...

Overview This page gives a description of the input section that controls and modifies how a molecular dynamics run is done. The MD input section is optional; all the user need do is add a "do dynamics" instruction in the command options and the code will automatically launch a molecular dynamics run,...

This page gives a description of the input section that controls the "Nudged Elastic Band" (NEB) transition state finder. This is a complicated calculation that requires very careful input. It involves multiple images in a "chain-of-states" calculation, and the generation of the intermediate states between the reactant and product geometries...