Solid state IR and Raman as well as aqueous solution state Raman spectra are reported for the linear di-amino acid peptide L-aspartyl-L-glutamic acid (L-Asp-L-Glu); the solution state Raman spectrum has also been obtained for the N,O-deuterated derivative. SCF-DFT calculations at the B3-LYP/cc-pVDZ level established that the structure and vibrational spectra of L-Asp-L-Glu can be interpreted us...

Contents 1. Introduction 2. Organic Chemistry a. Skeleton Structures and extensions thereof b. Molecular Orbitals and molecular interactions c. Carbenes in terms of this formalism 3. Wavefunction-based methods for computation of electronic structure a. Hartree-Fock scheme for approximating electronic structure b. Improvements on this theory c. Relationship to Organic Chemistry d. Difficulties i...

Discrete Fourier Transform (DFT) is one of the core operations in digital signal processing and communication systems. Many fundamental algorithms can be realized by DFT, such as convolution, spectrum estimation, and correlation. Furthermore, DFT is widely used in standard embedded system applications such as wireless communication protocols requiring Orthogonal Frequency Division Multiplexing ...

A modified frequency hopping signaling scheme has recently received a considerable attention by the designers of power line communication systems because of its insensitivity to frequencyselective and time-variant attenuation and high level of interference. In frequency hopping system, the increase of the data rate without increase of the hop rate is possible only if the receiver can detect all...

Subsystem density-functional theory (DFT) is an emerging technique for calculating the electronic structure of complex molecular and condensed phase systems. In this topical review, we focus on some recent advances in this field related to the computation of condensed phase systems, their excited states, and the evaluation of many-body interactions between the subsystems. As subsystem DFT is in...

Structural characterization of poly-l-lactic acid (P(L)LA) and poly(glycolic acid) (PGA) oligomers containing three units was carried out with an atomistic approach. Oligomer structures were first optimized through quantum chemical calculations, using density functional theory (DFT); rotational barriers concerning dihedral angles along the chain were then investigated. Diffusion coefficients of...

Although the discrete Fourier transform (DFT) precoded Alamouti (DPA) scheme with limited feedback offers numerous benefits in the Rayleigh fading channel, this scheme inherently generates geometric mean distortion due to the error exponential of the DFT precoding (DP). Consequently, the receiver suddenly losses the average received channel power. Instead of the conventional DPA scheme, we prop...

The question of how density functional theory (DFT) compares with Hartree-Fock (HF) for the computation of momentum-space properties is addressed in relation to systems for which (near) exact Kohn-Sham (KS) and HF one-electron matrices are known. This makes it possible to objectively compare HF and exact KS and hence to assess the potential of DFT for momentum-space studies. The systems conside...

An unified array architecture is described for computation of DFT, DHT, DCT and DST using a modified CORDIC (CoOrdinate Rotation DIgital Computer) arithmetic unit as the basic Processing Element (PE). All these four transforms can be computed by simple rearrangement of input samples. Compared to five other existing architectures, this one has the advantage in speed in terms of latency and throu...