Assessment of W1 and W2 theories for the computation of electron affinities, ionization potentials, heats of formation, and proton affinities

The performance of two recent {\em ab initio} computational thermochemistry schemes, W1 and W2 theory [J.M.L. Martin and G. de Oliveira, J. Chem. Phys. 111, 1843 (1999}], is assessed for an enlarged sample of thermochemical data consisting of the ionization potentials and electron affinities in the G2-1 and G2-2 sets, as well as the heats of formation in the G2-1 and a subset of the G2-2 set. We find W1 theory to be several times more accurate for ionization potentials and electron affinities than commonly used (and less expensive) computational thermochemistry schemes such as G2, G3, and CBS-QB3: W2 theory represents a slight improvement for electron affinities but no significant one for ionization potentials. The use of a two-point $A+B/L^5$ rather than a three-point $A+B/C^L$ extrapolation for the SCF component greatly enhances the numerical stability of the W1 method for systems with slow basis set convergence. Inclusion of first-order spin-orbit coupling is essential for accurate ionization potentials and electron affinities involving degenerate electronic states: inner-shell correlation is somewhat more important for ionization potentials than for electron affinities, while scalar relativistic effects are required for the highest accuracy. The mean deviation from experiment for the G2-1 heats of formation is within the average experimental uncertainty. W1 theory appears to be a valuable tool for obtaining benchmark quality proton affinities.Comment: Journal of Chemical Physics, in press (303115JCP). 2 RevTeX files, first is text and tables, second is E-PAPS tables S-1 through S-5. Additional supplementary material (total energies, basis function exponents) available at http://theochem.weizmann.ac.il/web/papers/w1w2.htm

Fully ab initio atomization energy of benzene via W2 theory

The total atomization energy at absolute zero, (TAE$_0$) of benzene, C$_6$H$_6$, was computed fully {\em ab initio} by means of W2h theory as 1306.6 kcal/mol, to be compared with the experimentally derived value 1305.7+/-0.7 kcal/mol. The computed result includes contributions from inner-shell correlation (7.1 kcal/mol), scalar relativistic effects (-1.0 kcal/mol), atomic spin-orbit splitting (-0.5 kcal/mol), and the anharmonic zero-point vibrational energy (62.1 kcal/mol). The largest-scale calculations involved are CCSD/cc-pV5Z and CCSD(T)/cc-pVQZ; basis set extrapolations account for 6.3 kcal/mol of the final result. Performance of more approximate methods has been analyzed. Our results suggest that, even for systems the size of benzene, chemically accurate molecular atomization energies can be obtained from fully first-principles calculations, without resorting to corrections or parameters derived from experiment.Comment: J. Chem. Phys., accepted. RevTeX, 12 page

Dokaz virusa newcastleske bolesti molekularnim postupkom FTA-PCR

The feasibility of using Flinders Technology Associates (FTA) filter papers to store the Newcastle disease virus (NDV), infected allantoic fluid (AF) and tissue samples, for the molecular detection of NDV by reverse transcriptase - polymerase chain reaction (RT-PCR) - was investigated. An FTA card is a cotton based cellulose membrane, with lyophilized chemicals that lyse the viruses and bacteria. The viral RNA was detectable from FTA cards up to a concentration of 107.6 EID50/100 μL (a 100 times dilution of 109.6 EID50/100 μL of initial stock). The inactivated virus remained stable on the cards for up to 30 days, both at room temperature and 4 ºC. NDV was detected by RT-PCR from all the FTA imprints of the caecal tonsils, kidney, proventriculus, spleen, trachea, faecal swabs and intestinal lesions of NDV-suspected birds. NDV was inactivated upon contact with FTA, as shown by the inability of the virus to propagate in embryonated eggs and its inability to infect chicken embryo fibroblast culture. In conclusion, FTA cards are suitable for collecting and transporting NDV infected samples, without cold storage. The virus inactivated in FTA cards, however, is a suitable source of viral RNA for molecular detection and characterization.Istražena je mogućnost uporabe Flinders tehnologije s filtrirnim papirom za pohranjivanje alantoisne tekućine zaražene virusom newcastleske bolesti i uzoraka tkiva radi molekularnog dokazivanja toga virusa lančanom reakcijom polimerazom uz prethodnu reverznu transkripciju (RT-PCR). Flinders kartica celulozna je membrana pripravljena na osnovi pamuka s liofiliziranim kemikalijama koje liziraju viruse i bakterije. Virusna RNA mogla se na takvoj kartici dokazati u količini od 107,6 EID50/100 μL (100 puta manje razrjeđenje od 109,6 EID50/100 μL osnovne suspenzije). Inaktivirani virus bio je stabilan na karticama tijekom 30 dana pri sobnoj temperaturi i 4 ºC. Virus je bio dokazan RT-PCR-om u svima Flinders tehnologijom pripravljenim otiscima cekalnih tonzila, bubrega, voljke, slezene, dušnika, obriscima fecesa i crijevnih lezija ptica sumnjivih na newcastlesku bolest. Virus je bio inaktiviran nakon dodira s FT fifi ltrirnim papirom što je bilo potvrđeno činjenicom da se nije više mogao uzgojiti u kokošjim embrijima ni na kulturi fibroblasta podrijetlom od kokošjih embrija. Zaključuje se da su FT papirići prikladni za uzimanje i prijenos uzoraka koji sadrže virus newcastleske bolesti bez potrebe pohranjivanja u hladnom prostoru. Virus inaktiviran na FT papiriću (kartici) odgovarajući je izvor virusne RNA za njegov molekularni dokaz i identifikaciju

2,4-Bis(4-bromo­phen­yl)-3-aza­bicyclo­[3.3.1]nonan-9-one

The title compound, C20H19Br2NO, shows a chair–chair conformation for the aza­bicycle with an equatorial disposition of the 4-bromo­phenyl groups [dihedral angle between the aromatic rings = 16.48 (3)°]. In the crystal, a short Br⋯Br contact [3.520 (4) Å] occurs and the structure is further stabilized by N—H⋯O hydrogen bonds and C—H⋯O inter­actions

2,4-Bis(4-chloro­phen­yl)-3-aza­bicyclo­[3.3.1]nonan-9-one

In the mol­ecular structure of the title compound, C20H19Cl2NO, the mol­ecule exists in a twin-chair conformation with equatorial dispositions of the 4-chloro­phenyl groups on both sides of the secondary amino group; the dihedral angle between the aromatic ring planes is 31.33 (3)°. The crystal structure is stabilized by N—H⋯O inter­actions, leading to chains of molecules

Comment on: "Estimating the Hartree-Fock limit from finite basis set calculations" [Jensen F (2005) Theor Chem Acc 113:267]

We demonstrate that a minor modification of the extrapolation proposed by Jensen [(2005): Theor Chem Acc 113:267] yields very reliable estimates of the Hartree-Fock limit in conjunction with correlation consistent basis sets. Specifically, a two-point extrapolation of the form $E_{HF,L}=E_{HF,\infty}+A(L+1)\exp(-9\sqrt{L})$ yields HF limits $E_{HF,\infty}$ with an RMS error of 0.1 millihartree using aug-cc-pVQZ and aug-cc-pV5Z basis sets, and of 0.01 millihartree using aug-cc-pV5Z and aug-cc-pV6Z basis sets.Comment: Theoretical Chemistry Accounts, in pres

A Comparative Study of Latin Square Design Under Fuzzy Environments Using Trapezoidal Fuzzy Numbers

This paper deals with the problem of Latin Square Design (LSD) test using Trapezoidal Fuzzy Numbers (Tfns.).  The proposed test is analysed under various types of trapezoidal fuzzy models such as Alpha Cut Interval, Membership Function, Ranking Function, Total Integral Value and Graded Mean Integration Representation.  Finally a comparative view of the conclusions obtained from various test is given.  Moreover, two numerical examples having different conclusions have been given for a concrete comparative study.   Keywords: LSD, Trapezoidal Fuzzy Numbers, Alpha Cut, Membership Function, Ranking Function, Total Integral Value, Graded Mean Integration Representation.   AMS Mathematics Subject Classification (2010): 62A86, 62F03, 97K8

One-Factor ANOVA Model Using Trapezoidal Fuzzy Numbers Through Alpha Cut Interval Method

Most of our traditional tools in descriptive and inferential statistics is based on crispness (preciseness) of data, measurements, random variable, hypotheses, and so on.  By crisp we mean dichotomous that is, yes-or-no type rather than more-or-less type.  But there are many situations in which the above assumptions are rather non-realistic such that we need some new tools to characterize and analyze the problem.  By introducing fuzzy set theory, different branches of mathematics are recently studied.  But probability and statistics attracted more attention in this regard because of their random nature.  Mathematical statistics does not have methods to analyze the problems in which random variables are vague (fuzzy). In this regard, a simple and new technique for testing the hypotheses under the fuzzy environments is proposed.  Here, the employed data are in terms of trapezoidal fuzzy numbers (TFN) which have been transformed into interval data using  interval method and on the grounds of the transformed fuzzy data, the one-factor ANOVA test is executed and decisions are concluded.  This concept has been illustrated by giving two numerical examples. Keywords: Fuzzy set, , Trapezoidal fuzzy number (TFN), Test of hypotheses, One-factor ANOVA model, Upper level data, Lower level data