Top institutions in chemistry

	Institution	Papers	Citations	Citations per paper
1	Scripps Research Institute	2,152	76,119	35.37
2	Harvard University	2,824	97,402	34.49
3	California Institute of Technology	2,086	69,935	33.53
4	Massachusetts Institute of Technology	3,700	109,467	29.59
5	Northwestern University	2,977	85,182	28.61
6	University of California, Berkeley	5,161	139,202	26.97
7	Stanford University	2,790	71,516	25.63
8	University of California, Los Angeles	2,220	51,499	23.20
9	University of California, Santa Barbara	2,174	50,380	23.17
10	University of Washington	2,353	53,608	22.78
11	University of Michigan	2,778	61,359	22.09
12	Georgia Institute of Technology	2,432	52,353	21.53
13	University of Minnesota	3,471	69,067	19.90
14	University of Texas at Austin	3,153	61,822	19.61
15	University of Illinois	4,310	81,057	18.81
16	University of Wisconsin, Madison	3,463	62,390	18.02
%3D17	Swiss Federal Institute of Technology (ETH), Zurich	4,701	83,137	17.68
%3D17	Pennsylvania State University	3,025	53,481	17.68
19	Max Planck Society	11,175	195,651	17.51
20	Imperial College London	3,365	58,904	17.50

The data above were extracted from the Essential Science Indicators database of Thomson Reuters. This database, currently covering the period January 1999 to June 2009, surveys only journal articles (original research reports and review articles) indexed by Thomson Reuters.

Articles are assigned to a category based on the journals in which they were published and the Thomson Reuters journal-to-category field-definition scheme. Both articles tabulated and citation counts to those articles are for the period indicated. Naturally, institutions publishing large numbers of papers have a greater likelihood of collecting more citations than those publishing fewer papers. This ranking is by citations per paper (impact), among those institutions that have collected 50,000 or more citations in chemistry during the period. For papers with multiple institutional addresses, each institution receives full, not fractional, citation credit. Essential Science Indicators lists institutions ranked in the top 1 per cent for a field over a given period, based on total citations.

For the current version, 919 institutions are listed in the field of chemistry, meaning that a total of 91,900 institutions were surveyed to obtain the results. Of the 919 institutions, 43 collected 50,000 or more citations. The ranking by citations per paper (impact) seeks to reveal heavy hitters based on per-paper influence, not mere output. US institutions account for 17 of the 20, while Switzerland, Germany and the UK have one institution each.

For more information on the Essential Science Indicators database, see http://scientific.thomsonreuters.com/ products/esi