Finally, the calculation is characterized as abInitioSCF. Alternatives might be
semiempiricalSCF or dft.
Attributes
The attributes of such a calculation are:
• Methodology—allows for deviations from the normal type of SCF calculation.
• spinType—RHF, UHF, or ROHF
• basisSet—as defined by the PNNL Basis Set Exchange.
Child Elements of Calculation
The child elements of an SCF calculation are:
• energies—core nuclear-nuclear interaction, electronic energy, total energy, etc.
• properties—system properties and atom properties
• waveFunction—orbital energies, orbital symmetry, coefficients, etc.
The energies are all labeled by their “type” attribute. For example, cs:totalPotential is a potential energy for nuclear motion in the Born-Oppenheimer
approximation and is commonly just called the total energy in quantum calculations. The advantage of using a Uniform Resource Identifier (URI) here is that it
gives uniqueness to the variable being described.
A large variety of properties (possibly expectation values) could be associated
with a quantum calculation. We divide these properties into system properties like
dipole moment and atom properties like mullikenCharges, A systemProperty has
attributes—“name” and “unit” where name, for example, is cs:dipoleMomentX
denoting the X component of the total dipole moment and unit is cs:debye.
An atomProperty also has attributes “name” and “unit” in addition to the attribute propertyCount which indicates how many atoms follow with properties. The
attributes of an atom property are the moleculeId and the atomId which uniquely
identify the atom (atom indices or id’s are unique only for the specific molecule that
the atom is a member of). The value of the atomProperty is the content of the
associated XML property element.
With quantum calculations there may be no connection table identifying a
“molecule” since a molecule of the molecular system is defined by CSX as the
collection of atoms forming a connected graph. For certain quantum calculations
there may only be a molecularSystem with child atoms and no “molecule” or
“coordination”, “bond”, etc. This is acceptable as valid CSX. It is preferred,
however, to define a connection table, if possible.
waveFunction
The wave function example in Fig. 6. shows the result for the above 3–21 G
calculation with its orbitals, etc. The far right side of the display is cut off and not all
orbital energies, symmetries, etc. are shown.
A Portal for Quantum Chemistry Data …
15
semiempiricalSCF or dft.
Attributes
The attributes of such a calculation are:
• Methodology—allows for deviations from the normal type of SCF calculation.
• spinType—RHF, UHF, or ROHF
• basisSet—as defined by the PNNL Basis Set Exchange.
Child Elements of Calculation
The child elements of an SCF calculation are:
• energies—core nuclear-nuclear interaction, electronic energy, total energy, etc.
• properties—system properties and atom properties
• waveFunction—orbital energies, orbital symmetry, coefficients, etc.
The energies are all labeled by their “type” attribute. For example, cs:totalPotential is a potential energy for nuclear motion in the Born-Oppenheimer
approximation and is commonly just called the total energy in quantum calculations. The advantage of using a Uniform Resource Identifier (URI) here is that it
gives uniqueness to the variable being described.
A large variety of properties (possibly expectation values) could be associated
with a quantum calculation. We divide these properties into system properties like
dipole moment and atom properties like mullikenCharges, A systemProperty has
attributes—“name” and “unit” where name, for example, is cs:dipoleMomentX
denoting the X component of the total dipole moment and unit is cs:debye.
An atomProperty also has attributes “name” and “unit” in addition to the attribute propertyCount which indicates how many atoms follow with properties. The
attributes of an atom property are the moleculeId and the atomId which uniquely
identify the atom (atom indices or id’s are unique only for the specific molecule that
the atom is a member of). The value of the atomProperty is the content of the
associated XML property element.
With quantum calculations there may be no connection table identifying a
“molecule” since a molecule of the molecular system is defined by CSX as the
collection of atoms forming a connected graph. For certain quantum calculations
there may only be a molecularSystem with child atoms and no “molecule” or
“coordination”, “bond”, etc. This is acceptable as valid CSX. It is preferred,
however, to define a connection table, if possible.
waveFunction
The wave function example in Fig. 6. shows the result for the above 3–21 G
calculation with its orbitals, etc. The far right side of the display is cut off and not all
orbital energies, symmetries, etc. are shown.
A Portal for Quantum Chemistry Data …
15