Hypertext Dalton 2.0 manual - Theoretical Chemistry, KTH

Chapter 1
Introduction
The dalton program system is designed to allow convenient, automated determination of
a large number of molecular properties based on an HF, DFT, MP2, coupled cluster, or
MCSCF reference wave function. Additions to the Dalton 2.0 release include density functional
theory implemented fully up to quadratic response theory for closed-shell systems, as
well as second derivatives for properties involving perturbation-dependent basis sets such a
molecular Hessians, magnetizabilities and nuclear shieldings. Also available is the NEVPT2
approach (the n-electron valence second-order perturbation theory) for calculating accurate
energetics of multireference-based systems including also dynamic electron correlation,
and highly accurate MP2-R12 methods are available for high-accuracy energetics of singlereference
dominated closed-shell systems.
The program consists of seven separate components, developed more or less independently.
hermit is the integral generator, generating ordinary atomic and molecular
integrals appearing in the time-independent, non-relativistic Schrödinger equation, as well
as an extensive number of integrals related to different molecular properties. eri is a vectorized
and distribution-oriented integral generator that may be invoked in certain calculations,
in particular in integral-direct coupled cluster calculations. sirius is the (MC)SCF wave
function optimization part, and is described comprehensively in the METECC-94 book [1].
abacus evaluates the second-order molecular properties of interest for SCF and MCSCF
wave functions as well density-functional theory, in particular second-order static molecular
properties in which the basis set depends on the applied perturbation. response is
a general-purpose program for evaluating response functions, up to cubic response functions
for (MC)SCF wave functions, quadratic response for DFT, and linear response for the
Second-Order Polarization Propagator Approximation (SOPPA) and Second-Order Polarization
Propagator Approximation with Coupled Cluster Singles and Doubles Amplitudes -
SOPPA(CCSD). A new density functional theory module has been added in the 2.0 release
of the program. Existing modules have been extended with the NEVPT2 and the MP2-R12
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