Thermodynamics - Maple Help
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QuantumChemistry

  

Thermodynamics

  

compute the thermodynamic properties of a molecule

  

 

Calling Sequence

Parameters

Description

Examples

Calling Sequence

Thermodynamics(molecule, method, options)

Parameters

molecule

-

list of lists; each list has 4 elements, the string of an atom's symbol and atom's x, y, and z coordinates

method

-

name/procedure where name is one of 'HartreeFock', 'DensityFunctional', 'RDMFunctional','ActiveSpaceCI',  'ActiveSpaceSCF', 'CoupledCluster', 'FullCI','MP2', 'Variational2RDM', 'Parametric2RDM',  'ContractedSchrodinger'

options

-

(optional) equation(s) of the form option = value where option is one of temperature, symmetry_number, or any valid option of the chosen method

Description

• 

Thermodynamics computes the thermodynamic properties of a molecule such as energy, enthalpy, entropy, free energy, heat capacity, electronic energy, zero-point energy (ZPE) and rotational temperatures (theta[A], theta[B], theta[C]).

• 

The optional temperature keyword can be used to set the temperature in K.  The default is 298.15 K.

• 

The optional symmetry_number keyword can be used to set the symmetry number of the molecule.  The default is 1.

Outputs

The table of following contents:

energy

-

float -- energy in J/mol

enthalpy 

-

float -- enthalpy in J/mol

entropy

-

float -- entropy in J/(mol K)

free_energy

-

float -- free energy of the system in J/mol

heat_capacity

-

float -- heat capacity of the system in J/(mol K)

electronic_energy

-

float -- electronic energy in J/mol

zpe

-

float -- zero-point energy in J/mol

θA 

-

float -- rotational temperature (in K) for principle axis A

θB 

-

float -- rotational temperature (in K) for principle axis B

θC

-

float -- rotational temperature (in K) for principle axis C

Examples

withQuantumChemistry:

Define the geometry of the molecule hydrogen fluoride

molecule   H, 0, 0, 0.55, F, 0, 0, +0.55 ;

Optimize the geometry of the molecule

moleculeH,0,0,−0.55000000,F,0,0,0.55000000

(1)

molecule2,output  GeometryOptimizationmolecule,'HartreeFock':

molecule2;

H,0,0,−0.55000000,F,−1.2034917710−11,6.2571891710−11,0.40546311

(2)

Using the command Thermodynamics, we can compute the molecule's thermodynamic properties

thermo  Thermodynamicsmolecule2, 'HartreeFock';

thermotablefree_energy=2.58849971108Jmol,entropy=365.61292814JmolK,electronic_energy=2.58802975108Jmol,zpe=26667.73973739Jmol,heat_capacity=20.78615124JmolK,θB=27.75734190K,enthalpy=2.58740963108Jmol,θC=27.75734190K,energy=2.58743442108Jmol

(3)

See Also

HartreeFock
DensityFunctional
RDMFunctional
MP2
CoupledCluster

FullCI
ActiveSpaceCI
ActiveSpaceSCF
Variational2RDM
Parametric2RDM
ContractedSchrodinger