Siam Quantum (SQ) is an ab initio quantum chemistry program that uses quantum mechanics to determine the total energy and wave function of molecules within the framework of HarteeFock, Density Function Theory, and MP2 method.
Recent News

(July 25, 2017) The new GGA exchange functional
See our manuscript at >>> https://arxiv.org/abs/1706.01343 <<< T.Chachiyo and H.Chachiyo "Simple and accurate exchange energy for density functional theory"
Posted Sep 19, 2017, 4:09 PM by teepanis

(August 15, 2016) The Chachiyo's Formula
After making quite a buzz in July (see Physics Today's article "A simpler ingredient for a complex calculation", which kindly mentioned our research paper in JCP "Communication: Simple and ...
Posted Nov 28, 2017, 12:49 PM by teepanis

(May 12, 2016) DFT is now avaiable
Density Functional Theory is now available. Currently, LDA and Hybrid are supported such as Slater Exchange, VWN5, and HF+Slater hybrid. The results should be practically identical to the well ...
Posted May 12, 2016, 4:12 AM by teepanis

(Feb 29, 2016) New Method for Finding Excitation Energies
At last, Siam Quantum supports excited states, quantum molecular dynamics, and uniform external electric field. Please give the option EXCITE, QMD, and EF=EX,EY,EZ a try. See Download ...
Posted Mar 15, 2016, 12:55 PM by teepanis

(Feb 26, 2016) Seeking Collarboration
We are seeking research collaboration to develop new methods to explore electronic properties of molecules, or to customize the Siam Quantum code to fit your prospective applications. Visiting scholars are ...
Posted Feb 25, 2016, 7:06 PM by teepanis
 Features
 Develop
source code and documentation originally for academic purposes in order
to introduce Thai students to the field of electronic structure
calculations
 Calculate
HartreeFock, DFT, and MP2 energies of molecules with the numerical results in excellent agreement with the standard quantum chemistry software such as GAMESS
 DFT is available with various functionals such as the Dirac exchange, the VWN correlation, and the simplest yet accurate electron correlation energy, the socalled “Chachiyo's formula”.
 Perform post SCF calculations such as electron density, molecular orbital, and dipole moment
 Very Fast and support parallel calculation on multiple CPUs
 Geometry optimization and simple population analysis
 Quantum Molecular Dynamics
 Support External Uniform Electric Field
 Excited Energies and Oscillator Strength
 Minimum Energy Crossing Point (MECP)
 Free (GPL License), support both Linux and Windows
Ongoing  ESP Charge Fit
 MP2 gradient
Future  Spectroscopic parameter prediction
 Support periodic system such crystal and carbon nanotube, especially at MP2 level
 Graphic User Interface (GUI)
 A book on electronic structure theory (in Thai language
