The simplest type of ab initio electronic structure calculation is the Hartree – Fock ( HF ) scheme, an extension of molecular orbital theory, in which the correlated electron – electron repulsion is not specifically taken into account ; only its average effect is included in the calculation.

* μ < sub > e </ sub > is the average molecular weight per electron, which depends upon the chemical composition of the star.

* Director, the spatial and temporal average of the orientation of the long molecular axis within a small volume element of liquid crystal

The local nematic director, which is also the local optical axis, is given by the spatial and temporal average of the long molecular axes

A molecular orbital describes the behavior of one electron in the electric field generated by the nuclei and some average distribution of the other electrons.

This has a numerical value which is the average molecular mass of the molecules in the substance multiplied by Avogadro's constant approximately 6. 022 × 10 < sup > 23 </ sup >.

The most common units of molar mass are g / mol because in those units the numerical value equals the average molecular mass in units of u.

Conversion factor of average molecular mass to molar mass:

average molecular mass in u

Molar mass is most often theoretical and average molecular mass is most often experimental )

Many chemists use molecular mass as a synonym of molar mass, differing only in units ( see average molecular mass below ).

Because a mole of molecules may contain a variety of molecular masses due to natural isotopes, the average mass is usually not identical to the mass of any single molecule.

The molecular mass of a molecule which happens to contain heavier isotopes than the average molecule in the sample can differ from the molar mass by several mass units.

The average molecular mass ( sometimes abbreviated as average mass ) is another variation on the use of the term molecular mass.

The average molecular mass and the molar mass of a particular substance in a particular sample are in fact numerically identical and may be inter-converted by Avogadro's constant.

It should be noted, however, that the molar mass is almost always a computed figure derived from the standard atomic weights, whereas the average molecular mass, in fields that need the term, is often a measured figure specific to a sample.

The use of average atomic masses derived from the standard atomic weights found on a standard periodic table will result in an average molecular mass, whereas the use of isotopic masses will result in a molecular mass consistent with the strict interpretation of the definition, i. e. that of a single molecule.

if a substantial fraction of the dust is orbiting about the Earth, only about one third the above-mentioned average velocity should be used in deriving the mass.

Most naturally occurring elements exist as a mixture of isotopes, and the average atomic mass of this mixture determines the element's atomic weight.

On average, the Atlantic is the saltiest major ocean ; surface water salinity in the open ocean ranges from 33 to 37 parts per thousand ( 3. 3 – 3. 7 %) by mass and varies with latitude and season.

Osteoporosis is defined by the World Health Organization ( WHO ) in women as a bone mineral density 2. 5 standard deviations below peak bone mass ( 20-year-old sex-matched healthy person average ) as measured by DEXA ; the term " established osteoporosis " includes the presence of a fragility fracture.

The relative atomic mass ( historically and commonly also called " atomic weight ") of an element is the average of the atomic masses of all the chemical element's isotopes as found in a particular environment, weighted by isotopic abundance, relative to the atomic mass unit ( u ).

For example, the relative atomic mass of chlorine is 35. 453 u, which differs greatly from a whole number due to being made of an average of 76 % chlorine-35 and 24 % chlorine-37.

Of the human body's solid components after drying and burning of organics ( as for example, after cremation ), about a third of the total " mineral " mass remaining, is the approximately one kilogram of calcium that composes the average skeleton ( the remainder being mostly phosphorus and oxygen ).

With an average atomic weight of ( for hydrogen-1 ), hydrogen is the lightest element and its monatomic form ( H < sub > 1 </ sub >) is the most abundant chemical substance, constituting roughly 75 % of the Universe's baryonic mass.

One scientist estimates the extinction may be 10, 000 times the background extinction rate ( the average between mass extinction events ).

The risk of such injuries is increased in patients who have below average body mass index or have a history of prior abdominal surgery.

A stricter interpretation does not equate the two, as the mass of a single molecule is not the same as the average of an ensemble.

Nostalgic Yankee readers of Erskine Caldwell are today informed by proud Georgians that Tobacco Road is buried beneath a four-lane super highway, over which travel each day suburbanite businessmen more concerned with the Dow-Jones average than with the cotton crop.

The average Democratic politician, especially in the country districts, is hungry for the spoils of office.

The national average is more than $4 and that figure is considered by experts in the mental health field to be too low.

Carbondale is in the Herrin-Murphysboro-West Frankfort labor market, where unemployment has been substantially higher than the national average.

But for the average citizen, unfortunately, this is one of science's worst-marked channels, full of tricky currents and unknown depths.

I am firmly convinced that considering the average quality of teachers in this country, the profession is grossly overpaid.

Of these states the average `` change-over '' point ( at which a car is substituted for allowances ) is 13,200 miles per year.

The average of states' rates is $.076 per mile.

Rhode Island's rate of $.07 per mile is considerably lower than reimburseable rates in the federal government and in industry nationally which approximate a $.09 per mile average.

Such payments shall be made to small domestic producers of lead as long as the market price for common lead at New York, New York, as determined by the Secretary, is below 14-1/2 cents per pound, and such payments shall be 75 per centum of the difference between 14-1/2 cents per pound and the average market price for the month in which the sale occurred as determined by the Secretary.

Such payments shall be made to small domestic producers of zinc as long as the market price for prime western zinc at East Saint Louis, Illinois, as determined by the Secretary, is below 14-1/2 cents per pound, and such payments shall be 55 per centum of the difference between 14-1/2 cents per pound and the average market price for the month in which the sale occurred as determined by the Secretary.

With respect to nighttime assignments, the degree of skywave service and interference is determined by skywave curves ( figs. 1 and 2 of sec. 3.190 of the rules ) giving average skywave values.

The minimum cost for an average one-story, 7-room house with basement, is likely to run $1500 above the cost of the heating alone.

This is if outdoor temperatures have a high average of 95 degrees.

You'll need more if the high average is above that, less if it's below.

On this first venture the central storage is 20,000 gallons, in two tanks, or an average of 400 gallons for each of the 50 homes.

The average charge for this additional insurance coverage is roughly $1.00 a day.

It is well to bear in mind that gasoline will cost from $.80 to $.90 for the equivalent of a United States gallon and while you might prefer a familiar Ford, Chevrolet or even a Cadillac, which are available in some countries, it is probably wiser to choose the smaller European makes which average thirty, thirty-five and even forty miles to the gallon.

Your chauffeur's expenses will average between $7.00 to $12.00 a day, but this charge is the same whether you rent a 7-passenger Cadillac limousine or a 4-passenger Peugeot or Fiat 1800.

Since most European cars average more miles per gallon of gasoline than American cars, it naturally follows that the cost per kilometer for these models will be less, but the greater seating capacity of the large American cars will equalize this, provided your group is sufficiently large to fill a 7-passenger limousine.

The ratio of the measured antenna temperature change during a drift scan across the moon to the average brightness temperature of the moon over the antenna beam ( assuming that the brightness temperature of the sky is negligible ) was found, by graphical integration of the antenna directivity diagram, to be 0.85.

If one assumes that the average flux did not change between measurements, a mass-distribution curve is obtained which relates the flux of particles larger than a given radius to the inverse 7/2 power of the radius.