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Introduction to ExaChem
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**ExaChem** is a suite of scalable electronic structure methods to perform ground and excited-state calculations on molecular systems. 
These methodologies are implemented using the Tensor Algebra for Many-body Methods (`TAMM <https://github.com/NWChemEx/TAMM>`_) library. 
TAMM is a parallel tensor algebra library for performance-portable development of scalable electronic structure methods that can be run on modern exascale computing platforms. 
ExaChem  currently includes implementations of: Hartree-Fock (HF), MP2, CC2, CCSD, CCSD(T), CCSD-Lambda, EOM-CCSD, RT-EOM-CCSD, GFCCSD and double unitary coupled-cluster (DUCC). 
ExaChem and TAMM are actively being developed and maintained at the Pacific Northwest National Laboratory (`PNNL <https://pnnl.gov>`_) and distributed as open-source under the terms of the Apache License version 2.0.