Own ethanol and NH3 small teaching examples, xTB6.7.1 edcfbbe official Intel binary. Three short MD trajectories, nominal40steps at0.5fs,20native dumps,not convergedstatisticalsampling. Native approximatepath12images/cyclelimit5 retains endpointoverlapNaN diagnostic;onlyfinitecoordinatesandenergies,notconvergedsaddle/rates. Modefollowing7 actualnativecompleted after privateformatadapter from projectednativeplainHessian andexactH/Nmass;eigenfrequencyandmasscomparedtoJSON,10decimalHessianroundingsplits6zeroeigenvalues<0.1cm-1 while6vibrationalmodesmatch1e-3cm-1 gate. Nativebinarynormalmodefilegeneratedlocally,notdistributed;sourceconverterandnativeplainHessianareprovided. Source modef.f90/wrmodef.f90/hessian.F90 fixededcfbbe. Originalmode1failureandanalysisoffbyone20vs21preservedprivately. Noexecutable/restartbinary/sharedsoftwarechange/customerdata.
