TY - JOUR

T1 - FALCON: A method for flexible adaptation of local coordinates of nuclei

AU - König, C.

AU - Hansen, Mads B.

AU - Godtliebsen, Ian H.

AU - Christiansen, O.

N1 - Funding information: We are grateful to Christoph R. Jacob for the coordinate and Hessian data for the alanine oligomers as well as support in the generation of at-localized coordinates. C.K. acknowledges funding by a Feodor - Lynen research fellowship from the Alexander von Humboldt Foundation as well as a post-doctoral grant from the Carlsberg Foundation. O.C. acknowledges support from the Lundbeck Foundation, the Danish National Research Foundation, the Danish e-infrastructure Cooperation (DeiC), and the Danish Council for Independent Research through a Sapere Aude III Grant No. DFF - 4002-00015.

PY - 2016/2/21

Y1 - 2016/2/21

N2 - We present a flexible scheme for calculating vibrational rectilinear coordinates with well-defined strict locality on a certain set of atoms. Introducing a method for Flexible Adaption of Local COordinates of Nuclei (FALCON) we show how vibrational subspaces can be "grown" in an adaptive manner. Subspace Hessian matrices are set up and used to calculate and analyze vibrational modes and frequencies. FALCON coordinates can more generally be used to construct vibrational coordinates for describing local and (semi-local) interacting modes with desired features. For instance, spatially local vibrations can be approximately described as internal motion within only a group of atoms and delocalized modes can be approximately expressed as relative motions of rigid groups of atoms. The FALCON method can support efficiency in the calculation and analysis of vibrational coordinates and energies in the context of harmonic and anharmonic calculations. The features of this method are demonstrated on a few small molecules, i.e., formylglycine, coumarin, and dimethylether as well as for the amide-I band and low-frequency modes of alanine oligomers and alpha conotoxin.

AB - We present a flexible scheme for calculating vibrational rectilinear coordinates with well-defined strict locality on a certain set of atoms. Introducing a method for Flexible Adaption of Local COordinates of Nuclei (FALCON) we show how vibrational subspaces can be "grown" in an adaptive manner. Subspace Hessian matrices are set up and used to calculate and analyze vibrational modes and frequencies. FALCON coordinates can more generally be used to construct vibrational coordinates for describing local and (semi-local) interacting modes with desired features. For instance, spatially local vibrations can be approximately described as internal motion within only a group of atoms and delocalized modes can be approximately expressed as relative motions of rigid groups of atoms. The FALCON method can support efficiency in the calculation and analysis of vibrational coordinates and energies in the context of harmonic and anharmonic calculations. The features of this method are demonstrated on a few small molecules, i.e., formylglycine, coumarin, and dimethylether as well as for the amide-I band and low-frequency modes of alanine oligomers and alpha conotoxin.

UR - http://www.scopus.com/inward/record.url?scp=84960898400&partnerID=8YFLogxK

U2 - 10.1063/1.4941846

DO - 10.1063/1.4941846

M3 - Article

VL - 144

JO - Journal of Chemical Physics

JF - Journal of Chemical Physics

SN - 0021-9606

IS - 7

M1 - 074108

ER -