Tecnai on-line help manual -- Options - UT Southwestern

<strong>Tecnai</strong> on-line help Options 97Options Software version 2Interplanar angleThe interplanar angle is the angle between the two d-spacings. The value for the interplanar angle (indegrees) can be determined with the on-line measurement or entered by hand.SetupPressing the Setup buttons brings up the Match constraints dialog in which the limits on deviations areset for the match between d-spacings and interplanar angle.CalculateWhen the Calculate button is pressed, the d1, d2 and interplanar angle are matched against calculationsof d-spacings an their interplanar angles, and possible matching zone axes are determined.Calculated valuesUnder calculated values are listed the matches of the calculations:• Indices for the best matches for d1 and d2• Calculated d-spacings for d1 and d2• Calculated interplanar angle between matches for d1 and d2 spacings• Ratio between matches for d1 and d2 spacingsResultant zoneThe resultant zone list contains all matching zone axes. The contents of this list is copied to the Twozoneindexing dialog when OK is pressed.OKPressing OK exits from the Zone-axis calculator dialog, while keeping the newly defined match for thezone axis. The data like d-spacings, interplanar angle and stage tilts are stored in the zone memory. Thestage axes are read when the OK button is pressed. It is important, therefore, to keep in mind that thestage tilts at that particular moment must be such that they coincide with the orientation of the zone axis.CancelPressing Cancel exits from the Zone axis calculator indexing dialog, without changing any of the values.7.5.3 Match constraints dialogAbsolute Distance Error LimitThe absolute distance error limit determines by how much a calculated d-spacing may differ from themeasured one for it to be accepted as a possible match for one of the d-spacings.Ratio Distance ErrorThe ratio distance error limit determines by how much the calculated ratio between d-spacing 1 and d-spacing 2 may deviate from the ratio of the measured spacings.