## 10.2 Fullerenes

### Single Fullerene Construction

`nanocap_single_fullerene.py` is an example script to construct and save a fullerene. The code is shown below.

    '''
    -=-=-=-=-=-=-=-=-=-=-=-=-=NanoCap=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
    Copyright Marc Robinson  2014
    -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-

    A script to construct a fullerene

    Input:
        N_carbon = Number of carbon atoms
        dual_lattice_force_field = force field
                                   for dual lattice
        carbon_force_field = force field
                            for carbon lattice
        dual_lattice_mintol= energy tolerance for
                             dual lattice optimisation
        dual_lattice_minsteps= steps for dual lattice
                                optimisation
        carbon_lattice_mintol=as above for carbon lattice
        carbon_lattice_minsteps=as above for carbon lattice
        optimiser=optimsation algorithm
        seed = seed for initial cap generation

    Output:
        xyz files containing dual lattice
        and carbon lattice

    -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
    '''

    import sys,os,random,numpy
    from nanocap.core.minimisation import DualLatticeMinimiser, \
                                          CarbonLatticeMinimiser
    from nanocap.structures.fullerene import Fullerene
    from nanocap.core.output import write_xyz

    N_carbon = 200

    dual_force_field = "Thomson"
    carbon_force_field = "EDIP"
    dual_lattice_mintol=1e-10
    dual_lattice_minsteps=100
    carbon_lattice_mintol=1e-10
    carbon_lattice_minsteps=100
    optimiser="LBFGS"
    seed = 12345

    my_fullerene = Fullerene()
    my_fullerene.construct_dual_lattice(N_carbon=N_carbon,seed=seed)
    my_fullerene.set_fix_pole(False)
    my_fullerene.set_nfixed_to_equator(0)

    Dminimiser = DualLatticeMinimiser(FFID=dual_force_field,
                                      structure = my_fullerene)
    Dminimiser.minimise(my_fullerene.dual_lattice,
                        min_type=optimiser,
                        ftol=dual_lattice_mintol,
                        min_steps=dual_lattice_minsteps)

    outfilename = "C{}_dual_lattice.xyz".format(N_carbon)
    write_xyz(outfilename,my_fullerene.dual_lattice)

    my_fullerene.construct_carbon_lattice()

    Cminimiser = CarbonLatticeMinimiser(FFID=carbon_force_field,
                                        structure = my_fullerene)

    Cminimiser.minimise_scale(my_fullerene.carbon_lattice)
    Cminimiser.minimise(my_fullerene.carbon_lattice,
                        min_type=optimiser,
                        ftol=carbon_lattice_mintol,
                        min_steps=carbon_lattice_minsteps)

    outfilename = "C{}_carbon_atoms.xyz".format(N_carbon)
    write_xyz(outfilename,my_fullerene.carbon_lattice)
    outfilename = "C{}_carbon_atoms_constrained.xyz".format(N_carbon)
    write_xyz(outfilename,my_fullerene.carbon_lattice,constrained=True)

### Constructing Multiple Fullerenes

`nanocap_bulk_fullerenes.py` is an example script to perform a structure search to construct and save multiple fullerenes. The code is shown below.

    '''
    -=-=-=-=-=-=-=-=-=-=-=-=-=NanoCap=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
    Copyright Marc Robinson  2014
    -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-

    A script to construct a series of
    fullerenes

    Input:
        N_carbon = number of carbon atoms
                    in the fullerene
        dual_lattice_force_field = force field
                                   for dual lattice
        carbon_force_field = force field
                            for carbon lattice
        dual_lattice_mintol= energy tolerance for
                             dual lattice optimisation
        dual_lattice_minsteps= steps for dual lattice
                                optimisation
        carbon_lattice_mintol=as above for carbon lattice
        carbon_lattice_minsteps=as above for carbon lattice
        optimiser=optimsation algorithm
        seed = seed for initial cap generation
        N_nanotubes = required number of structures
        N_max_structures = maximum number of possible
                            structures to search through
        basin_climb = True/False - climb out of
                      minima
        calc_rings = True/False - calculate rings for
                      each structure

    Output:
        -A structure log in myStructures.out

        -xyz files containing the carbon lattices

    -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
    '''

    import sys,os,random,numpy
    from nanocap.core.minimisation import DualLatticeMinimiser, \
                                          CarbonLatticeMinimiser
    from nanocap.core.minimasearch import MinimaSearch
    from nanocap.structures.fullerene import Fullerene
    from nanocap.core.output import write_points

    N_carbon = 200
    dual_lattice_minimiser = "Thomson"
    carbon_lattice_minimiser = "EDIP"
    seed = 12345

    N_fullerenes = 5
    N_max_structures = 20
    basin_climb = True
    calc_rings = True

    dual_lattice_minimiser = "Thomson"
    carbon_lattice_minimiser = "EDIP"
    dual_lattice_mintol=1e-10
    dual_lattice_minsteps=100
    carbon_lattice_mintol=1e-10
    carbon_lattice_minsteps=100
    optimiser="LBFGS"
    seed = 12345

    my_fullerene = Fullerene()
    my_fullerene.construct_dual_lattice(N_carbon=N_carbon,seed=seed)
    my_fullerene.construct_carbon_lattice()
    my_fullerene.set_fix_pole(False)
    my_fullerene.set_nfixed_to_equator(0)

    Dminimiser = DualLatticeMinimiser(FFID=dual_lattice_minimiser,
                                      structure = my_fullerene,
                                      min_type= "LBFGS",
                                      ftol = 1e-10,
                                      min_steps = 10)

    Cminimiser = CarbonLatticeMinimiser(FFID=carbon_lattice_minimiser,
                                      structure = my_fullerene,
                                      min_type= "LBFGS",
                                      ftol = 1e-10,
                                      min_steps = 10)

    Searcher = MinimaSearch(Dminimiser,
                             carbon_lattice_minimiser= Cminimiser,
                             basin_climb=basin_climb,
                             calc_rings=calc_rings)

    Searcher.start_search(my_fullerene.dual_lattice,
                          N_fullerenes,
                          N_max_structures)

    Searcher.continue_search(my_fullerene.dual_lattice,
                             N_fullerenes,
                             N_max_structures)

    Searcher.structure_log.write_log(os.getcwd(),"myStructures.out")

    for i,structure in enumerate(Searcher.structure_log.structures):
        outfilename = "C{}_carbon_atoms_{}"
        outfilename = outfilename.format(structure.carbon_lattice.npoints,i)
        write_points(outfilename,
                     structure.carbon_lattice,
                     "xyz")