--- name: "sc_MolecularEnergy" section: "3" platform: "linux" package: "libsc-doc" version: "2.3.1-22" release: "Debian 12 (Bookworm)" platforms: ["linux"] url: "https://new.carta.tech/sc_MolecularEnergy" --- # sc\_MolecularEnergy(3) The MolecularEnergy abstract class inherits from the Function class. ## NAME sc::MolecularEnergy - The **MolecularEnergy** abstract class inherits from the **Function** class. ## SYNOPSIS `#include ` Inherits **sc::Function**. Inherited by **sc::SumMolecularEnergy**, **sc::TaylorMolecularEnergy**, and **sc::Wavefunction**. ### Public Member Functions **MolecularEnergy** (const **MolecularEnergy** &)\ **MolecularEnergy** (const **Ref**\< **KeyVal** \> &)\ The **KeyVal** constructor. **MolecularEnergy** (**StateIn** &)\ void **save\_data\_state** (**StateOut** &)\ Save the base classes (with save\_data\_state) and the members in the same order that the **StateIn** CTOR initializes them. void **set\_checkpoint** ()\ Set up checkpointing. void **set\_checkpoint\_file** (const char \*)\ void **set\_checkpoint\_freq** (int freq)\ bool **if\_to\_checkpoint** () const\ Check if need to checkpoint. const char \* **checkpoint\_file** () const\ int **checkpoint\_freq** () const\ **MolecularEnergy** & **operator=** (const **MolecularEnergy** &)\ virtual double **energy** ()\ A wrapper around **value()**;. virtual **Ref**\< **Molecule** \> **molecule** () const\ virtual **RefSCDimension** **moldim** () const\ void **guess\_hessian** (**RefSymmSCMatrix** &)\ **Compute** a quick, approximate hessian. **RefSymmSCMatrix** **inverse\_hessian** (**RefSymmSCMatrix** &)\ **RefSymmSCMatrix** **hessian** ()\ If a molecule hessian object is given, it will be used to provide a hessian. int **hessian\_implemented** () const\ void **set\_x** (const **RefSCVector** &)\ Set and retrieve the coordinate values. **RefSCVector** **get\_cartesian\_x** ()\ Return the cartesian coordinates. **RefSCVector** **get\_cartesian\_gradient** ()\ Return the cartesian gradient. **RefSymmSCMatrix** **get\_cartesian\_hessian** ()\ Return the cartesian hessian. **Ref**\< **MolecularCoor** \> **molecularcoor** ()\ virtual void **symmetry\_changed** ()\ Call this if you have changed the molecular symmetry of the molecule contained by this **MolecularEnergy**. **Ref**\< **NonlinearTransform** \> **change\_coordinates** ()\ An optimizer can call change coordinates periodically to give the function an opportunity to change its coordinate system. void **print\_natom\_3** (const **RefSCVector** &, const char \*t=0, std::ostream &o=**ExEnv::out0**()) const\ Nicely print n x 3 data that are stored in a vector. void **print\_natom\_3** (double \*\*, const char \*t=0, std::ostream &o=**ExEnv::out0**()) const\ void **print\_natom\_3** (double \*, const char \*t=0, std::ostream &o=**ExEnv::out0**()) const\ virtual void **print** (std::ostream &=**ExEnv::out0**()) const\ Print information about the object. ### Protected Member Functions void **failure** (const char \*)\ virtual void **set\_energy** (double)\ This is just a wrapper around set\_value(). virtual void **set\_gradient** (**RefSCVector** &)\ These are passed gradients and hessian in cartesian coordinates. virtual void **set\_hessian** (**RefSymmSCMatrix** &)\ void **x\_to\_molecule** ()\ void **molecule\_to\_x** ()\ ### Protected Attributes **Ref**\< **PointGroup** \> **initial\_pg\_**\ int **print\_molecule\_when\_changed\_**\ ### Additional Inherited Members ## Detailed Description The **MolecularEnergy** abstract class inherits from the **Function** class. It computes the energy of the molecule as a function of the geometry. The coordinate system used can be either internal or cartesian. \ ## Constructor & Destructor Documentation ### sc::MolecularEnergy::MolecularEnergy (const Ref\< KeyVal \> &) The **KeyVal** constructor. - `molecule` A **Molecule** object. There is no default. - `coor` A **MolecularCoor** object that describes the coordinates. If this is not given cartesian coordinates will be used. For convenience, two keywords needed by the **MolecularCoor** object are automatically provided: natom3 and matrixkit. - `value_accuracy` Sets the accuracy to which values are computed. The default is 1.0e-6 atomic units. - `gradient_accuracy` Sets the accuracy to which gradients are computed. The default is 1.0e-6 atomic units. - `hessian_accuracy` Sets the accuracy to which hessians are computed. The default is 1.0e-4 atomic units. - `hessian` Specifies a **MolecularHessian** object that is used to compute the hessian. If this **MolecularEnergy** specialization does not provide a hessian of its own, and a hessian is needed, then this keyword must be specified. - `guess_hessian` Specifies a **MolecularHessian** object that is used to compute a guess hessian. Guess hessians are used to improve the rate of convergence of optimizations. If this keyword is not specified, and a **MolecularCoor** object is given by `coor`, then the guess hessian is obtained from the **MolecularCoor** object. If neither this nor `coor` are given, then **Function::guess\_hessian** is used, which returns a unit matrix. - `print_molecule_when_changed` If true, then whenever the molecule's coordinates are updated they will be printed. The default is true. - `checkpoint` If true, then this object will be checkpointed during its evaluation. Not all implementations of **MolecularEnergy support checkpointing. The default is false.** - `checkpoint_file` **Specifies the name of the file into which this object will be checkpointed. Default is '\.ckpt', where '\' is the name of the input file without '.in'.** - `checkpoint_freq` **Specifies how often this object to be checkpointed. Only matters for objects which are computed iteratively. Default is 1.** ## Member Function Documentation ### Ref\< NonlinearTransform \> sc::MolecularEnergy::change\_coordinates ()` [virtual]` **An optimizer can call change coordinates periodically to give the function an opportunity to change its coordinate system. A return value of 0 means the coordinates were not changed. Otherwise, a transform object to the new coordinate system is return. The function object applies the transform to any objects it contains. This will obsolete the function data.** **Reimplemented from sc::Function.** ### void sc::MolecularEnergy::guess\_hessian (RefSymmSCMatrix &)` [virtual]` **Compute a quick, approximate hessian.** **Reimplemented from sc::Function.** ### RefSymmSCMatrix sc::MolecularEnergy::hessian ()` [virtual]` **If a molecule hessian object is given, it will be used to provide a hessian.** **Reimplemented from sc::Function.** ### int sc::MolecularEnergy::hessian\_implemented () const` [virtual]` **Reimplemented from sc::Function.** ### RefSymmSCMatrix sc::MolecularEnergy::inverse\_hessian (RefSymmSCMatrix &)` [virtual]` **Reimplemented from sc::Function.** ### virtual Ref\< Molecule \> sc::MolecularEnergy::molecule () const` [virtual]` **Reimplemented in sc::Wavefunction.** ### virtual void sc::MolecularEnergy::print (std::ostream & = ExEnv::out0`()`) const` [virtual]` **Print information about the object.** **Reimplemented from sc::Function.** **Reimplemented in sc::TaylorMolecularEnergy, sc::Wavefunction, sc::CLKS, sc::HSOSKS, sc::UKS, sc::MBPT2, sc::MBPT2\_R12, sc::PsiWavefunction, sc::CLHF, sc::CLSCF, sc::HSOSHF, sc::HSOSSCF, sc::OSSHF, sc::OSSSCF, sc::SCF, sc::TCHF, sc::TCSCF, sc::UHF, sc::UnrestrictedSCF, and sc::OneBodyWavefunction.** ### void sc::MolecularEnergy::save\_data\_state (StateOut &)` [virtual]` **Save the base classes (with save\_data\_state) and the members in the same order that the StateIn CTOR initializes them. This must be implemented by the derived class if the class has data.** **Reimplemented from sc::Function.** **Reimplemented in sc::SumMolecularEnergy, sc::TaylorMolecularEnergy, sc::CLKS, sc::HSOSKS, sc::UKS, sc::MBPT2, sc::MP2BasisExtrap, sc::MBPT2\_R12, sc::PsiWavefunction, sc::PsiSCF, sc::PsiCCSD, sc::PsiCCSD\_T, sc::CLHF, sc::CLSCF, sc::HSOSHF, sc::HSOSSCF, sc::OSSHF, sc::OSSSCF, sc::SCF, sc::TCHF, sc::TCSCF, sc::UHF, sc::UnrestrictedSCF, sc::ExtendedHuckelWfn, sc::OneBodyWavefunction, sc::HCoreWfn, and sc::Wavefunction.** ### virtual void sc::MolecularEnergy::set\_gradient (RefSCVector &)` [protected]`, ` [virtual]` **These are passed gradients and hessian in cartesian coordinates. The gradient and hessian in internal coordinates are computed.** **Reimplemented from sc::Function.** ### virtual void sc::MolecularEnergy::set\_hessian (RefSymmSCMatrix &)` [protected]`, ` [virtual]` **Reimplemented from sc::Function.** ### void sc::MolecularEnergy::set\_x (const RefSCVector &)` [virtual]` **Set and retrieve the coordinate values.** **Reimplemented from sc::Function.** **Reimplemented in sc::SumMolecularEnergy.** ### virtual void sc::MolecularEnergy::symmetry\_changed ()` [virtual]` **Call this if you have changed the molecular symmetry of the molecule contained by this MolecularEnergy.** **Reimplemented in sc::MBPT2, sc::CLSCF, sc::HSOSSCF, sc::OSSSCF, sc::SCF, sc::TCSCF, sc::UnrestrictedSCF, sc::OneBodyWavefunction, and sc::Wavefunction.** ## Author **Generated automatically by Doxygen for MPQC from the source code.**