orpheus

Hello. Where can I get data on polymorphs of a certain chemical? For instance any give medical chemical. There most likely are databases that contain such info, and maybe even structures, like there is the Protein Data Bank with structures of proteins. I'd appreaciate it if some one could give a hint to where such info can be accessed and how. Cheers.

There's a little bit more information on this here: http://www.spectroscopynow.com/coi/cda/detail.cda?id=18428&type=EducationFeature&chId=2&page=1

What does the acronym SNP refer to here? Some lab-on-the-chip practice?

you need a vacation man..

You need to approach the question with limits, when M and D approach infinity M approaches 1. But a magnifying lense with a focal poit at infinity is not a maginifying lense at all.

Hey. Thanks to you both. Now, as you suspected, my question originates from attempting to understand exactly what IR spectroscopy is based on. I realized that the absorption rate and frequency would be unique for certain sructures, and therefore the method can be used as detection. But what I was not sure about was what happens on the more basic level. And now I believe, if I am not mistaken, that when the dipole receives the photon, it receives energy. Then it compensate the energy overload with either streching or bending. These compensate for the energy load because the atoms move to positions that that would not otherwise be energy favourable? Is this it? How does one calculate the amout of energy? For instance, if my sample is anhydrous hydrochloric acid (a dipole) and it is bombed with IR. The diatomic HCl can be considered a harmonic oscillator, as mentioned above, and the potential energy depends on the distance of the poles. These then can change either beause of geometrical (bending) reasons or because of the streching (distance). Shoud it not be calculable then?

reiterate, I do not understand the question..

Hello. This is my first post ever here, and I'm pretty sure it's not in the correct section, and I apologize for that. So the atoms in a molecule vibrate in relation to each other. And when IR radiation is absorbed by a molecule these vibrations increase. Apparently absorption only happens if there is a change in dipole moment. How do the streching and bending effects change dipole moment? Is it that streching adjusts the distance between the atoms or what?