= BDFWiki: Gaussian function based BDF (Beijing Density Functional) program package =
<<TableOfContents()>>

== Version history ==
The Gaussian function based BDF program started in 2009 based on several contributions from previous group members.

''Compared with other quantum chemistry programs, it mainly focuses on '''relativistic effects''' and '''excited-state properties''' of '''large molecules'''. ''

Currently, it is not open to everyone, since we are still trying to make it easier to use.

However, if you are interested in using it '''for the above problems''', please contact the authors for collaboration:

 * Wenjian Liu: https://www.researchgate.net/profile/Wenjian_Liu
 * Bingbing Suo: https://www.researchgate.net/profile/Bingbing_Suo
 * Zhendong Li: https://www.researchgate.net/profile/Zhendong_Li4
 * ..... 


== List of features ==
=== Current features ===
 * Relativistic Hamiltonians: sf-X2C/SOMF
 * R,RO,U SCF ([[scf]]): Hatree-Fock and DFT
 * Variants of TD-DFT ([[tddft]])
 * MP2 and Local MP2 based on fragmentations
 * Geometry optimization ([[bdfopt]])
 * MCSCF ([[mcscf]]): Multi-configuration self-consistent-field
 * Gradient ([[grad]]): SCF, DFT, TDDFT and (SA-)CASSCF analytic gradients 
 * Numerical Gradient ([[numgrad]]): Numerical gradient for SCF, DFT, TDDFT, MCSCF and Multi Reference methods in xianci module
 * MOs integrals transformation ([[traint]]): MOs integrals transformation for TDDFT, FULL-CI, MRCI, MRPT2 and other Post-HF methods.
 * VGMF-CI [[[vgmfci]]]: Vibrational General Mean Field Configuration interaction
 * NMR: Nuclear Magnetic Resonance 
 * MRCISD: from uncontracted to fully internally contracted MRCI,
 * MRPT2: Various MRPT2 methods include MS-NEVPT2/3, SDS-PT2, CB-MRPT2/3
 * CCSD,EOM-CCSD: Coupled Cluster Theory developed in Sihuan University (Prof. Fan Wang).
 * REM: Renormalize Exciton Method developed by Nanjing University. (Prof. Jing Ma. Prof. Haibo Ma)
 * NTO analyze: Natrual transition orbital analyze based on TDDFT/TDHF
 * Two diabatic states coupling to calculate energy transfer and charge transfer integrals. 

=== Package developed by other groups that are Interfaced or integrated into BDF ===
 * CC with SOC [[ccsdso]] (Fan Wang)
 * UND-MCSCF -- Developed by Mark Hoffman in North Dakota University
 * MCCEPA 
 * DETCI
 * Xi'an-CI Program [[xianci]] -- Developed by Zhenyi Wen, Yubin Wang, Zhengting Gan, Bingbing Suo and Yibo Lei in Northwest University 
 * GEBF -- Developed by Nanjing University
 * dlfind 

=== Under development ===
 * Response properties based on DFT ([[resp]]) (Zhendong Li)
 * [[NMR]] (Minghong Yuan)
 * [[Localizations]] (Hongyang Li)

=== Future development ===
 * [[Large-scale DFT/TD-DFT and heterogeneous computing]] (Bingbing Suo)
 * [[2C and 4C DHF/KS]] (Daoling Peng)
 * [[NMR and NSR]] (Yunlong Xiao)
 * [[QM/MM]] (Jun Gao)
 * Interface to dynamics (Jun Gao)


== Recent major changes ==
'''2014.10.08 by Zhendong Li: Various updates for SCF/TD-DFT/SOC ''' 

1. SCF enables fixed sign of MO coefficients during iterations by [isgnfix] and with respect to the read guess by [iaufbau=3]. This is useful in FINITE DIFFERENCE calculations.

2. TD-DFT with read guess and save eigenvectors for C(1) case by using [dvdread] and [dvddump]

3. The construction of X2C-based spin-orbit mean-field (SOMF) operator has been parallelized with OPENMP in soint_util

4. TD-DFT/SOC: iterative diagonalization of Hsoc in configuration space based on Davidson's algorithm allows to work in real algebra! This allows constructing very large effective Hamiltonians, and more efficient than the full diagonalization of Hermitian matrix with the dimension larger than 1000. ('''This is not fully tested yet, for the degenerate case, a special case must be taken to ensure the orthogonality in complex representation for degenerate states''')

5. TD-DFT/SOC: the transition dipole moment at the RPA level is enabled, which allows studying phosphorescence with state interaction. The results in general agree well with those obtained from quadratic response theory. '''But they do differ when some instabilities happen!'''

6. TD-DFT/SOC: state-selected active orbital projected Hsoc to stabilize ground state in SOC calculation by iact=1 and a proper eup=xxx eV for cut off.

'''2014.11.13-29 by Zhendong Li & Bingbing Suo & Yong Zhang : Extractors and Geometry optimizers '''

1. [[bdf_extractor.py]] for extracting useful information from BDF output. It is to be used for preparation interface for '''geometry optimization, nonadiabatic dynamics'''

2. An important step: '''geometry optimization''', see [[bdfopt]].

== Quick start ==
To get quick start, please refer to the examples in '''bdf-pkg/tests/input/'''.

 * [[Define your own basis set]]

 * [[Change the amount of HF exchange in functionals]]

 * [[Nonabelian symmetry]]
 
 * Characters in BDF input are case insensitive. However, the name of basis set file should be capital letters such as "CC-PVDZ". The environment variables such as BDFHOME, BDF_TMPDIR, BDF_WORKDIR should be capital letters. 

== Programs ==
The following programs are listed in '''bdf-pkg/database/program.dat'''. If there is any problem or question, please contact the corresponding authors.
||'''[[Program]]''' ||'''Brief introduction''' ||'''Main authors''' ||
||[[compass]] ||几何结构 ||Bingbing Suo ||
|| ||
||[[xuanyuan]] ||积分计算 ||Bingbing Suo ||
|| ||
||[[scf]] ||SCF (KS and HF) ||Bingbing Suo, Zhendong Li ||
|| ||
||[[traint]] ||积分变换 ||Bingbing Suo ||
|| ||
||[[tddft]] ||TD-DFT ||Zhendong Li, Bingbing Suo ||
|| ||
||[[resp]] ||DFT-response theory ||Zhendong Li ||
|| ||
||mp2 ||MP2 ||Bingbing Suo ||
|| ||
||localmo ||localization || ||
|| ||
||[[bdfopt]] ||Geometry optimization ||Bingbing Suo, Zhendong Li ||
|| ||
||[[nmr]] ||NMR ||Minghong Yuan ||
|| ||
||mcscf ||MCSCF || Bingbing Suo||
|| ||
||[[grad]] || Analytic Gradients - RHF and MCSCF ||Bingbing Suo ||
||[[numgrad]] || Numerical Gradients - RHF, MCSCF, Xi'an-CI methods ||Yibo Lei ||
|| ||
||expandmo ||Expand MO coefficients from a small basis set to a large basis set ||Bingbing Suo ||
|| ||
||[[atom]] ||Atom calculations ||Zhendong Li ||
|| ||
||drt ||DRT ||Yibo Lei, Yubin Wang, Bingbing Suo, Zhenyi Wen ||
||mrci ||MRCI ||Yibo Lei, Yubin Wang, Bingbing Suo, Zhenyi Wen ||
|| [[xianci]] || MRCI from uncontracted to fully internally contracted MRCI, Various MRPT2 methods || Yibo Lei, Yubin Wang, Bingbing Suo, Zhenyi Wen||
|| ||
||dhf ||Dirac-HF ||Zhendong Li ||
||relscf ||REL-SCF ||Bingbing Suo ||
|| ||
||fci ||FCI without symmetry ||Zhendong Li ||
|| ||
||[[ccsdso]] ||CCSDSO ||Fan Wang ||
||eomipso ||EOM-IP-SO ||Fan Wang ||
||eomeaso ||EOM-EA-SO ||Fan Wang ||
||eomeeso ||EOM-EE-SO ||Fan Wang ||
|| ||
||libmath_test ||test for math libraries ||Zhendong Li ||
|| ||
||genfrag ||Fragments ||Bingbing Suo ||
|| ||
||mcmp2 ||Monte-Carlo MP2 (unfinished) ||Zhendong Li ||
|| ||
||[[vgmfci]] ||VGMFCI ||Bingbing Suo, Patrick Cassam-Chenaï||
|| ||
||mccepa ||MC-CEPA || ||
|| ||
||x2c ||useful Remove latter || ||
||traintmc ||AO-MO Integral transformation for undmcscf ||Bingbing Suo ||
||undmcscf ||MCSCF from undmol ||Bingbing Suo ||
||rhfscf ||??? || ||
||mrso ||Spin-orbital coupling based on GUGA, in developing ||Bingbing Suo ||
||trnx ||??? || ||
||guess ||Initial guess orbital ||Remove latter ||
||properties ||??? || ||
||reorderorb ||Reorder orbital for undmcscf ||Bingbing Suo ||
||socint ||Spin-orbital coupling integral ?? || ||
||contsi ||Constraint state interaction CI, in developing || ||
||strmcrcfgs ||String-CI (Hoffmann) ||interfaced ||
||strci ||String CI || ||
||norbord ||Interface for undmcscf || ||
||[[noxci]] ||non-orthogonal MRCID(with double excitation contracted ) ||Chao Huang ||
||[[nrcc]] ||non-relativistic restricted CCD/CCSD/EOM-CCSD||Chao Huang ||
||[[corr2]] ||(SR)MP2,Epstein-Nesbet PT2,IEPA, etc double excitation correlation (Energy& Coefficient)   ||Chao Huang ||



== Source ==
In general, there are two kinds of folder in bdf-pkg/source. One type of folders with suffix "_util" (such as scf_util) corresponds to folders that do not contain a main program. They contain library routines shared or used by different programs. The other type of folders (such as scf) corresponds to folders which contain a main.F90 program. Source codes in these folder are compiled and linked to an executable files with the name "foldername.x" and are saved in directory bdf-pkg/bin.

Folders in '''bdf-pkg/source''':
||'''Folder''' ||'''Description''' ||
||atom || ||
||atom_mod || ||
||atom_util || ||
||bdf_cvwint2e || ||
||bdf_opencl_util ||System util of OpenCL support in BDF ||
||bdf_rel1e || ||
||bdf_rel1e_NRpart || ||
||bdf_rel2e || ||
||bdf_relbas || ||
||bdf_relmod || ||
||bdf_relshl || ||
||bdf_x2c || ||
||c_util || ||
||cbmrpt2 || ||
||ccsdso || ||
||ccsdso_util || ||
||cdri_util || ||
||ci_util || ||
||cl_dft_kernel ||OpenCL kernels for DFT, C99 language ||
||class || ||
||compass || ||
||contsi || ||
||corr2 || ||
||detci || ||
||dft ||Share library of DFT, should be changed to dft_util ||
||dhf || ||
||dpdmrpt2 || ||
||drt || ||
||ecpint_util || ||
||eomeaso || ||
||eomeaso_util || ||
||eomeeso || ||
||eomeeso_util || ||
||eomipso || ||
||eomipso_util || ||
||erd ||Remove later ||
||erd_ACESIII ||Remove later ||
||eri_util ||Library for ERI and gradients calculation ||
||exact2c_util || ||
||extra_lib || ||
||f77_cg || ||
||f77_dftd3 || ||
||f77_util || ||
||f77_xc ||XC functional Fortran 77 code ||
||fci || ||
||flmo_util || ||
||fmm_util ||Faster multipole library - in developing ||
||geom_opt || ||
||grad_util ||Share library for gradients ||
||group_util ||Share library for point group untility ||
||icci_new_918 || ||
||icoord_mod || ||
||include ||Fortran and C head files ||
||int1e_util ||Library of 1e integrals ||
||int_util ||Library of 2e integrals ||
||lagrangian || ||
||libecctrip || ||
||libmath_f77 || ||
||libmath_mod || ||
||libmath_test || ||
||libmath_util || ||
||libmathc_util || ||
||libr || ||
||librcc || ||
||libundmol || ||
||list || ||
||localmo || ||
||mathlib || ||
||mccepa || ||
||mccepa_util || ||
||mcci || ||
||mcgugaci_util || ||
||mcmodule || ||
||mcmp2 || ||
||mcrcfgs || ||
||mcscf || ||
||mcscf_util || ||
||mctpdmcfg || ||
||mctrans || ||
||module || ||
||mp2 || ||
||mrci || ||
||mrso || ||
||nmr || ||
||nmr_mod || ||
||norbord || ||
||noxci || ||
||noxci_util || ||
||opdmcfg || ||
||orbhess || ||
||orbord || ||
||orbxcsfcfg || ||
||para_util ||Library for parallel calculation. ||
||pmrci || ||
||postscf || ||
||properties || ||
||relint1e_util || ||
||relint2e_util || ||
||relscf || ||
||reorderorb || ||
||resp ||driver of response ||
||resp_f77 || ||
||resp_mod || ||
||resp_util || ||
||respc_util || ||
||scf ||SCF program ||
||scf_util ||Library of SCF ||
||socint || ||
||soint_util || ||
||strci || ||
||strmcrcfgs || ||
||sys_util ||System libraries such as IO, system initialization ||
||tddft ||TDDFT ||
||tddft_props || ||
||tddft_util ||Share library of TDDFT ||
||tddftc || ||
||tidyorb || ||
||tools || ||
||tpdmcfg || ||
||traint || ||
||traint_util || ||
||traintmc || ||
||undmcscf || ||
||undmol_drv || ||
||undmol_util || ||
||vgmfci || electron-nuclei mean field configuration interaction routines ||
||x2c || ||
||xuanyuan || ||
||xianci || Interfaced with Xi'an-CI program developed in Northwest University ||
== Citations ==
'''Historical papers about the BDF package''':

W. Liu, G. Hong, D. Dai, L. Li, and M. Dolg, Theor. Chem. Acc. 96, 75 (1997).

W. Liu, F. Wang, and L. Li, J. Theor. Comput. Chem. 2, 257 (2003).

W. Liu, F. Wang, and L. Li, in Recent Advances in Relativistic Molecular Theory, Recent Advances in Computational Chemistry, Vol. 5, edited by K. Hirao and Y. Ishikawa (World Scientific, Singapore, 2004), p. 257.

W. Liu, F. Wang, and L. Li, in Encyclopedia of Computational Chemistry (electronic edition), edited by P. von Ragu\'e Schleyer, N. L. Allinger, T. Clark, J. Gasteiger, P. A. Kollman, H. F. Schaefer III, and P. R. Schreiner (Wiley, Chichester, UK, 2004).

'''Spin-adapted open-shell TD-DFT''':

Zhendong Li and Wenjian Liu, “Spin-adapted open-shell random phase approximation and time-dependent density functional theory. I. Theory”, J. Chem. Phys. 133, 064106 (2010).

Zhendong Li, Wenjian Liu, Yong Zhang, and Bingbing Suo, “Spin-adapted open-shell time-dependent density functional theory. II. Theory and pilot application”, J. Chem. Phys. 134, 134101 (2011).

Zhendong Li and Wenjian Liu, “Spin-adapted open-shell time-dependent density functional theory. III. An even better and simpler formulation”, J. Chem. Phys. 135, 194106 (2011).

'''Spin-flip TD-DFT''':

Zhendong Li and Wenjian Liu, “Theoretical and numerical assessments of spin-flip time-dependent density functional theory”, J. Chem. Phys. 136, 024107 (2012).

'''TD-DFT with SOC based on spin-free exact two-component (sf-X2C) and spin-orbit mean-field (SOMF) operator''':

Zhendong Li, Yunlong Xiao, and Wenjian Liu, “On the spin separation of algebraic two-component relativistic Hamiltonians”, J. Chem. Phys. 137, 154114 (2012).

Zhendong Li, Yunlong Xiao, and Wenjian Liu, “On the spin separation of algebraic two-component relativistic Hamiltonians: molecular properties”, J. Chem. Phys. 141, 054111 (2014).

Zhendong Li, Bingbing Suo, Yong Zhang, Yunlong Xiao, and Wenjian Liu, “Combining spin-adapted open-shell TD-DFT with spin-orbit coupling”, Mol. Phys. 111, 3741 (2013).

'''TD-DFT and pp-TDA based first-order nonadiabatic coupling matrix elements (fo-NACMEs)''':

Zhendong Li and Wenjian Liu, "First-order nonadiabatic coupling matrix elements between excited states: A Lagrangian formulation at the CIS, RPA, TD-HF, and TD-DFT levels", J. Chem. Phys. 141, 014110 (2014).

Zhendong Li, Bingbing Suo, and Wenjian Liu, "First-order nonadiabatic coupling matrix elements between excited states: II. Implementation and applications at the TD-DFT and pp-RPA levels", J. Chem. Phys. 141, 244105 (2014).

'''Fragment Local Molecular Orbital''':

Zhendong Li, Hongyang Li, Bingbing Suo, Wenjian Liu, "Localization of molecular orbitals: from fragments to molecule", Accounts of chemical research, 47(9), 2758-2767, 2014.

Hongyang Li, Wenjian Liu, Bingbing Suo, "Localization of open-shell molecular orbitals via least change from fragments to molecule", J. Chem. Phys. 146, 104104, 2017.