(N)Integrate help - convergence problem

*To*: mathgroup at smc.vnet.net*Subject*: [mg48694] (N)Integrate help - convergence problem*From*: Patrick Jemmer <patrick.jemmer at unn.ac.uk>*Date*: Thu, 10 Jun 2004 02:44:40 -0400 (EDT)*Sender*: owner-wri-mathgroup at wolfram.com

I am trying to do integrals such as the ones below, but am getting error messgaes.. can anyone help me out please? "NIntegrate :: ncvb : NIntegrate failed to converge to prescribed accuracy after 7 recursivebisections in r near r = 4.22449...." The outputs are as follows 0.531684 -0.993442 -0.461758 -0.0316842 -0.00655776 -0.038242 but are I guess nonsense, as they are non-converged. I'd be happy to use either Integrate or NIntegrate: whichever works! Many thanks, Patrick. --------------------------------------------------- (* KINETIC & POTENTIAL OPERATORS *) T[x_]:=(1/r^2)*D[ r^2*D[x, r], r ]; V := -1/r; (* WAVEFUNCTION *) Fit5g = Sqrt[ 0.0711280497855832 / E^(16*r^2) + 0.0950242005793304 / E^(4*r^2) + 0.09001525518121072 / E^r^2 + 0.011332742959622262 / E^(r^2/4) - 0.0003397835348217242 / E^(r^2/16) ]; (* CALCULATE ENERGIES *) TT5 = -(1/2)*Fit5g*T[Fit5g]//Simplify; VV5 = Fit5g*V*Fit5g //Simplify; KK5 = TT5 + VV5//Simplify; TTT5 = 4*Pi*r^2*TT5//Simplify; VVV5 = 4*Pi*r^2*VV5 //Simplify; KKK5 = TTT5+ VVV5//Simplify; TE5 = NIntegrate[ TTT5, {r, 0, Infinity} ] VE5 = NIntegrate[ VVV5, {r, 0, Infinity} ] EE5 = TE5 + VE5 //Simplify -------------------------------------------------------------------- Eur Chem Dr Patrick Jemmer BA (Hons) CertPostgradStudy MA (Cantab) MA (Oxon) MRSC MInstP MIMA CChem CPhys CMath LNCP MNCH (Lic) LHS LAPH FRSH AMWFH AMBAThH AMSHA AMSHR Senior Lecturer & Admissions Tutor (Computing) D110 Ellison Building School of Informatics Northumbria University NE1 8ST UK telephone: +44 (0)191-243-7679 facsimile: +44 (0)191-227-3362 Patrick.Jemmer at northumbria.ac.uk personal URL: http://www.alowvelkiconsulting.co.uk ---------------------------------------- Siihr u Frith sil; sy m'ture'sw fisol. Hy'l, Frith na'f eloyhimint, vappilimint'f flis : "Hlooza u Azla ye'' hririn sihn.Thanif sonni sy m'hreth." Ky' silla Frith fy m'las eloyhim flisla rui'. For God is good; he gives us light. And came they to Frith, calling unto him: "There is no life because the Lord is dead. We are doomed." For Frith it was that came down from the sky.