# How to calculate or where to get atomic spectral data.

1. Dec 25, 2008

### Gravitroid

I found atomic spectral data on the hydrogen atom, more specifically the first isotope of the hydrogen atom, protium. Beyond that, the data available on other isotopes of any atom doesn't seem to be eaisily available.

Here is a page on protium, http://en.wikipedia.org/wiki/Hydrogen_spectral_series
It lists all the various series of spectrum for the hydrogen atom.
But what about deuterium? or other isotopes?

Protium and Deuterium have different spectral fingerprints. How does one find the series for deuterium? Or go about calculating it?

2. Dec 25, 2008

### olgranpappy

A calculation that is similar to the one you found, but for deuterium (which differs in mass, M_d rather than M_p) would end up giving a spectrum that differs by a factor of
$$\frac{1+m_e/M_d}{1+m_e/M_p}$$
because it is the reduced mass which enters into the relative Schrodinger equation.

3. Dec 25, 2008

### Gravitroid

I tried the google method, and found almost nothing but articles that you must pay for.

Apparently the constant that I need is the rydberg constant for deuterium to calculate the spectral lines.

HOWEVER, I would like to be able to verify it with real numbers. Isn't there some list of spectral lines for each type of atom and their isotopes?

4. Dec 25, 2008

### Dr Transport

5. Dec 25, 2008

### olgranpappy

Yeah. The ratio of the rydberg constant for deuterium divided by the usual hydrogen one is the factor I wrote down. Of course, it's very close to one so the different in the spectra will be very small. Cheers.

6. Dec 25, 2008

### Gravitroid

Perfect! It has all the data.

NOW! How do I get the measured data for deuterium? I can only input element letter designations. H for hydrogen. Deuterium is what? D2 I have also seen it as H(2).

I looked for isotope options but saw nothing.
Anyone?

7. Dec 25, 2008

Staff Emeritus
Deuterium is the only isotope where spectral shifts are significant. It may well be difficult to find written down as the equation that relates hydrogen to deuterium lines is well known.

8. Dec 25, 2008

### Gravitroid

Uhh, but aren't equation's only as good as the data they are derived from?

I would imagine that todays technology could get much more precise measurements than say even 5 years ago.

Without the data behind the equation, the equation becomes meaningless due to the lack of physical proof about its source.

Isn't that a part of what we call "The Scientific Process?"

The set of data that proves the hypothesis, or equation.

I would just run down to the local lab and get the data myself. After trying to find it on the net, and not, but finding a billion places that show you in experiment how to get the data. Sorry I don't have access to any lab. Only the NIST.GOV site.

So now if I wanted to cite an article, or set of data that shows the proof of the rydberg constant for deuterium, I cannot.

I thought most academia required proofs, perhaps theres a massive encyclopedia of spectral signatures of all known atoms and isotopes?

If not, mabee someone should start one. A monumental task? Yes, but eventually it will happen. And one could start with only certain frequency ranges, or something to keep progress going, like using only stable isotopes at first.

Honestly, if I had access to a lab, I would do this in my spare time as a hobby, lol..

Last edited: Dec 25, 2008
9. Dec 26, 2008

### olgranpappy

What exactly do you mean by "the proof of the rydberg constant for deuterium"?

Honestly, as everyone knows, gaining access to a lab *is* the difficult part. Once you have that the rest is easy, grasshopper.

10. Dec 26, 2008

### Gravitroid

Nothing more than a source that shows actual mesured values of the deuterium atom showing measured spectral lines. No calculations, which means no using protiums spectrum with the rydberg constant for deuterium, to get the data.

LOL, if I were president everyone would have a lab. lol.

11. Jan 7, 2009