Facility Renovation
Both Phase I (renovation of space and installation of instrumentation) and Phase II (installation of closed loop cooling system) are now complete. The closed loop systems works well and mitigates the effect of fluctuating water pressure in the building.
Status of Facility Equipment
The Facility's equipment consists of the following:
All major equipment is presently in good working order. Both diffractometers have recently been realigned and the radiation detection chains recalibrated. During fiscal year (FY97) there were several instrumental difficulties. During the summer of 1996 and the spring of 1997 the Facility faced a number of problems. One of the cooling hoses popped off and caused a flood. All tubing has been replaced with Nalgene 980 0.5" braided tubing. There have been no water problems since then. The air conditioning was not working for part of the summer which caused the CAD4's generator to overheat and repeatedly shut itself off. The CAD4 MACH's interface power supply failed (under warranty). Nonius shipped a replacement card which I installed. The q drive motor also failed (under warranty) on the CAD4 MACH. This was replaced by a Nonius service engineer. During last Fall's meeting of the Users' Advisory Committee I mentioned a problem with the CAD4 that manifested itself during the alignment procedure. After much trouble shooting it was determined that the cable to the f axis motor had gone bad. This manifested itself at high k values (commonly used during the instrument alignment procedure). This problem required a visit by a Nonius service engineer and was successfully resolved in October 1996. In January 1997 the CAD4 again developed electromechanical difficulties. Again after considerable trouble shooting, the problem was determined to be the f axis motor (the contacts of the motor had simply worn through). Again the problem was resolved in March 1997 with a Nonius service engineer visit. Also in March, one of the motor control boards in the CAD4 interface went bad. I successfully diagnosed the problem and solved it by swapping the faulty motor control board with a new one. Quite recently, the tape backup on the SGI computer has developed problems. The error suggests a hardware problem. I am looking into this now.
The problems with the CAD4 f axis are age related. We should expect problems of this type caused by wear on moving parts or embrittlement of the wires and other electronic components to continue to manifest. It is my opinion that to avoid excessive down times in the future that the CAD4 should be put under service contract. In FY97 instrument maintenance costs were approximately $8300. The cost of a service contract is approximately $8600 per year. Since we are already spending that level of money on instrument maintenance, we should do so rationally. A service contract provides 2 visits per year, and free parts (with swap).
Tube Fatigue
During my recent realignment of the CAD4, I checked the intensity of the tube relative to some measurements I made just after installation of the CAD4 in May 1995. The X-ray tube in the CAD4 has lost 56% of it's original intensity. Assuming a linear dependence in time, the tube has lost an average of 2.3% of it's intensity per month. The resulting half life of the tube is 21.7 months. This is actually not bad for the life of an X-ray tube. As users, you should be aware that X-ray tubes are considered "consumables", and will represent a continuing expense for the Facility. Many crystallographers I have talked to expect to replace a tube every 12-18 months. To compensate for this loss of intensity, I am running the tube at 1600 W (I normally load the tube at 1000W). I will do this until the tube is no longer usable. I believe we can anticipate purchasing a at least one new MoKa tube within the next 6 months (about $3000).
The 486 supplied by Nonius used to run the diffractometers is a minimal system with little opportunity for upgradability (it uses obsolescent VLB technology, and the IDE disk controller is restricted to only two harddrives, each less than 540 MB in size). There is a good chance that we will run out of disk space by the end of the year. If usage continues to increase, I need to begin taking data off the disk periodically. While it is not mission critical, it is a convenience to leave data on the disk.
Statistics of Samples Submitted and Structures Solved
Usage of the Facility rose over the course of fiscal year 1997 (FY97). For FY96 there were 73 samples submitted. For FY97 there were 106 samples submitted, representing an increase of 45%. The number of structure determinations is not what I wish it was, but reflects the overall demand for this service in the user base. Most of the unit cell determinations were submitted originally as either data collections or structure determinations, but the samples submitted lacked sufficient quality to justify proceeding further with the analysis. When combining the number of samples charged at the unit cell determination rate with the number of unsuitable samples we arrive at the total number of samples which did not yield either data sets or structure determinations. This figure represents roughly 55% of the Facility's input stream.
Statistics for FY97
Samples Submitted 106 Structure Determinations 22 20.7% Data Collection Only 25 23.6% Unit Cell Determinations 30 28.3% Unsuitable Samples 29 27.4%
Below is a table of analogous information for the 1997 calendar year.
Statistics for Calendar Year 1997 (1 January - 23 October)
Samples Submitted 129 Structure Determinations 16 12.4% Data Collection Only 40 31.0% Unit Cell Determinations 34 26.4% Samples in Queue 8 6.2% Unsuitable Samples 27 20.9% Projects in Progress 4 3.1%
Financial Status of Facility
In January 1997 the Users' Advisory Committee met to review the fee schedule. The majority of the users decided to lower the fees for Department of Chemistry members, and leave the previous fee structure intact for users outside of the Department. This change was implemented 1 February 1997. The agreed upon fee schedule is as follows:
Rates for NCSU Department of Chemistry Users
Unit Cell Determination: $ 30 Data Collection Only $ 150 Low Temperature Data Collection Only $ 200 Complete Structure Determination $ 250 Low Temp Complete Struct. Determination $ 300
Rates for NCSU users in other departments, external academic, and users from private industry
Unit Cell Determination: $ 30 Data Collection Only $ 250 Complete Structure Determination $ 350 Low Temp Complete Struct. Determination $ 300 Liquid N2 cost $ 35/tank
In calendar year 1997 this change in fee structure has resulted in a loss of approximately $6300 in terms of lost revenue (from 35 data sets and 16 structures) and additional costs (liquid nitrogen charges). In addition, this fee structure was in contravention of University policy in that it charged differential rates for intra- versus extradepartmental users. An impending audit of the University by the IRS and state agencies, prompted a reorganization of the trust accounts for all of the Analytical Instrumentation Facilities (X-ray, Mass-Spec and NMR). As a consequence, the funds in the Facility account are now treated as state appropriated money. The positive side of this is that there are fewer stipulations on the structure of the account (the fee structure now complies with University policy). The negative is that the balance, strictly speaking, must be zero at the end of the fiscal year. However, both Dr. Osteryoung and Hanck of assured me though that it will not a problem to carry over funds from year to year if the following conditions are met: 1) There is no excessive balance one way or another; 2) A justification exists for the carryover. The net effect is that while there may be some volatility in the X-ray account, it should not be a problem for.
For FY97, the X-ray Facility expended slightly more than it took in. The major budget items were instrument maintenance, liquid nitrogen, supplies, conference/travel, computer software. The largest new expense is the cost of liquid nitrogen, which is now carried by the Facility.
Income/expenditure figures for FY97
Paid Invoices $ 15,750.00 Receivables $ 932.50 Total Income $ 16,682.50
Expenditures $ 16,865.24
Encumbrances $ 0.00
Net Profit/Loss $ -182.74
Trust Balance for FY97
Carried Forward from FY96 $ 3,095.78
Balance for FY97 $ -182.74
Net Balance (not including receivables) $ 1,980.54
Expenses for FY97 Broken Down by Category (sorted by magnitude)
Instrument Maintenance $ 8,290.41Most Recent Figures for FY98 (up thru September 1997)Liquid N2 $ 2,026.17
Supplies $ 1,982.58
Conference/Travel $ 1,812.20
Computer Software $ 1,343.02
Phone/FAX $ 950.20
Miscellaneous $ 460.56
Computer Hardware $ 0.00
Total $ 16,865.24
Currently, there is an outstanding receivables balance. I realize there will always be a lag in the financial statements, but some of these bills have been unpaid since July. I would appreciate an effort to make prompt payments of charges.
Paid Invoices $ 1,332.50Receivables $ 2,540.00
Total Income $ 3,872.50
Expenditures $ 3,143.52
Encumbrances $ 41.49
Total Expenses $ 3,185.01
Net Profit/Loss $ 687.49
Trust Balance for FY98
Carried Forward from FY97 $ 1,980.54
Balance for FY97 $ 687.49
Net Balance (not including receivables) $ 128.04
The Facility runs very near the zero balance all the time, with expenditures matching income. This situation, however, does not provide rational support for the replacement of expensive consumables like X-ray tubes. I am willing to see how this new fee schedule performs over the next year and review it in the Fall of 1998. Because complete structure determinations are not the major activity of the Facility, I think it would make sense to eventually consider a use based fee structure.
Other Accomplishments and Future Plans
Publications for 1997 resulting from work performed at NCSU in the 1996-1997 period
Methyl-Xanthines I. Anhydrous Theophylline. Yukiko Ebisuzaki, Paul D. Boyle, and Jennifer A. Smith Acta Cryst. C 1997, 777
Oxidation of a Vanadium(V)-dithiolate Complex to a Vanadium(V)-h2,h2-disulfenate Complex. Charles R. Cornman, Thad C. Stauffer, and Paul D. Boyle J. Amer. Chem. Soc. 1997, 5986.
Stabilization of the (p-indenyl)-Lead Bond: The First Structurally Authenticated Bis(h5-indenyl) Complex of a Posttransition Element, [{1,3-(SiMe3)2}2Pb]. Jason S. Overby, Timothy P. Hanusa, and Paul D. Boyle Angew. Chem. 1997, in press.
Structural and Electron Paramagnetic Resonance Studies of the Square Pyramidal to Trigonal Bipyramidal Distortion of Vanadyl Complexes Containing Sterically Crowded Schiff Base Ligands Charles R. Cornman, Katherine M. Geiser-Bush, Stephen P. Rowley, and Paul D. Boyle Inorg. Chem. 1997, accepted for publication.
a- and b-CuAlCl4: Framework Construction Using Corner Shared Tetrahedral Metal-Halide Building Blocks James D. Martin, Brian R. Leafblad, Roger M. Sullivan, and Paul D. Boyle Inorg. Chem. 1997, submitted for publication.
Intramolecular Photocycloaddition of a Tethered Bis-2,3-dihydro-4-pyridone: Stereochemistry and Reactivity of the Cycloadduct Daniel L. Comins, Yong Sup Lee, and Paul D. Boyle Tetrahedron Letters 1997, in press.
Computational Environment Development
Crystallographic Results Server
In October 1996, I launched the Crystallographic Results Server. The purpose of the server is to facilitate the delivery of softcopy structural results to users of the Facility. Structural results can now be accessed via AppleShare (for Mac users), file sharing (for Win95, Win3.11, Win NT users), NFS (for UNIX users), through the Facility's Web server (as previously available), as well as via conventional ftp methods. Dr. Cornman in particular has made good use of this resource.
I assisted the former NMR Facility Director, Dr. Kim Colson, in the implementation of an NFS based data sharing environment for the NMR Facility.
Software Development Efforts
My development of CGI programs to facilitate the data collection for the International Union of Crystallography's World Directory of Crystallographers, 10th edition (WDC10) was acknowledged in the hardcopy format of the WDC10. I will continue to improve this software as the occasion arises in collaboration with Dr. Yvon Le Page (yvon.le_page@nrc.ca), and Dr. Yves Epelboin (epelboin@lmcp.jussieu.fr).
Further along the lines of WWW programming, I modified an existing CGI program to assist former NMR Facility Director in creating an on line registration form for NMR minicourses. I do not know, however, if this has been much used since her departure.
Over the past year I have done a fair amount of CGI programming. This has been based on the post-query.c code included in the NCSA httpd server distribution. There are some problems with that code, and I thought it would be worthwhile to write a flexible and robust set of routines to process data from WWW FORMs. I have accomplished this goal, and will be the basis of any future CGI programming efforts.
I have written a program called 'chi90s' which searches through a CAD4 data file to find reflections which are suitable to use as y scan reflections. An additional feature of the program is that if a reflection meets certain preliminary criteria, but does not have a suitable c value, the program then calculates the c values for the non-Friedel symmetry equivalents. If one of these symmetry equivalents are suitable, then that reflection is output. This has been a useful utility program, as it saves time and effort in trying to find suitable y scan reflections. I announced the release of this program on the USENET sci.techniques.xtallography newsgroup in June, and it has since been noted in the Sincris Crystallographic Software database (http://www.lmcp.jussieu.fr/sincris-top/logiciel/) and in a list scientific software that runs under Linux (http://SAL.KachinaTech.COM/Z/4/CHI90S.html). A casual review of the ftp transfer logs indicates that approximately fifty to sixty groups from around the world have downloaded the program.
I am writing my own C language implementation of Duisenberg's direct space indexing algorithm (see A. J. M. Duisenberg J. Appl. Cryst. 1992, 25, 92-96). This method has shown more success in indexing twinned crystals. I have undertaken this project for several reasons: 1) Duisenberg does not release his source code, and that prevents me from porting and compiling the program to run on Facility computers; 2) I wanted to modify the program to be more flexible (i.e. use dynamic memory management for all data structures) and to implement some of my own extensions to make intelligent decisions when dealing with a sample that is probably twinned; 3) to deepen my understanding of the indexing process beyond a simple "tricks of the trade" understanding or what reading the literature can provide. This is a work in progress, and I have completed about a third to a half of the program.
I have also written a number of minor utilities, most notably a routine to derive distances from axial photo graphs, and a program to read the .raw file from the Rigaku powder diffractometer in MEAS and output it in a format which can be used by powder diffraction software used by the Martin group.
Future Plans
In order to provide better archiving and retrieval of structural results, I am planning to use an "Object Relational Database Management System" (ORDMS) to store structural data. The idea being that users can fill out a form on the Web and retrieve a structure or structures which fit a given search criteria. For example, I envision that a user could search on structure ID code, principal investigator name, student name, unit cell, unit cell volume, reduced cell volume, element type(s), formula, etc. The output would be HTML formatted pages which could be copy and pasted directly into word processor documents. The ORDMS software I have chosen is PostgreSQL 6.2, which is available for no charge over the Internet (see http://www.postgresql.org). I am currently designing the structure of the database, i.e. how the data is to be partitioned among internal tables.
I think it is also time to think about putting together another NSF equipment grant for a CCD based system. While we may have a hard time justifying a new instrument on usage levels alone, we may be able to justify it in terms crystallographic problems that certain types of samples tend to have. Namely, small or otherwise weakly diffracting crystals, twinning, and a systematic weakening of diffraction maxima for classes of reflections due to pseudotranslational symmetry. A CCD would be useful in surmounting all of these problems. Samples from Dr. Martin's group, in particular, almost always have pseudotranslational symmetry problems. In addition, if a hire is made of a crystallographic user for either the department head position and/or a junior appointment, a purchase of a diffractometer may be tied to start up funds, or at least give the proposal some more weight in increased usage.